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  • ASTROPHYSICS  (566)
  • Cell & Developmental Biology  (414)
  • Humans  (278)
  • 1985-1989
  • 1980-1984  (1,216)
  • 1965-1969
  • 1950-1954
  • 1930-1934  (42)
  • 1980  (1,216)
  • 1931  (42)
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  • 1985-1989
  • 1980-1984  (1,216)
  • 1965-1969
  • 1950-1954
  • 1930-1934  (42)
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  • 1
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    Electronic Resource
    An investigation of the nervous system as a possible factor in the regulation of ciliary activity of the lamellibranch gill (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 51 (1931), S. 147-193 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Certain variations of ciliary activity in the lamellibranch gill occur which are an intrinsic part of the gill tissue and which are due to causes other than environmental changes. Experimental and morphological evidence indicates that the central nervous system is not involved in the production of these variations.A comparative study of laterofrontal and lateral ciliated cells leads to the conclusion that the coordination impulse passes through the cytoplasm of the cell and that the velocity of the propagation wave is influenced by the number of cell walls per unit length through which it passes. It is suggested that the ciliary rootlets in the laterfrontal cells, due to their arrangement bring the impulse simultaneously to both rows of cilia within a single cell.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1050510104
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  • 2
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    The spermiogenesis of Succinea ovalis say, with special reference to the components of the sperm (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 51 (1931), S. 243-289 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: An investigation of the spermiogenesis of Succinea ovalis Say, a small terrestrial pulmonate, has revealed: 1) The germ cells are differentiated from indifferent germinal epithelial cells. In this form the germinal epithelium is a true epithelium, and not a syncytium. 2) Forty chromosomes are found in the spermatogonial divisions and twenty in the maturation divisions. 3) Early in spermiogenesis the proximal centriole penetrates through the spermatid nucleus and, with the oxychromatin, forms an intranuclear rod similar to that reported for certain prosobranches. The homology and significance of the rod are discussed. 4) Of the cytoplasmic structures, the mitochondria and the Golgi apparatus were followed through all stages of spermatogenesis. 5) At the maturation divisions the mitochondria are grouped into peculiar. thread-like structures. Some of the mitochondria take part in the formation of the sheath around the axial filament of the spermatozoon, while the remainder are sloughed off with the cytoplasmic remnant. 6) The Golgi apparatus consists of a number of banana-shaped rods closely grouped around the idiosome. Three to five Golgi rods are found in the spermatid stages. A portion of the Golgi apparatus and idisome (acroblast) forms the acrosome, and the Golgi remnant is discarded at the end of spermatogenesis. 7) In mature sperm both head and tail have a spiral structure. The origin and nature of the spirals are pointed out.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1050510107
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  • 3
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    Blood formation in the african lungfish, under normal conditions and under conditions of prolonged estivation and recoveryThis paper was awarded the Virginia Academy of Science research prize for 1930. (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 51 (1931), S. 319-371 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The blood cells of the African lungfish, Protopterus ethiopicus, are very large and resemble those of urodeles. Leucocytes are especially plentiful and rich in variety, including eosinophils, special eosinophils, [meta-eosinophils] with atypical granules, monocytes, thrombocytes, lymphocytes, and basophils.The chief hemocytopoietic organs are the spleen, intestine, and kidneys. The lungfish spleen, embedded in the wall of the stomach, represents an intermediate phylogenetic stage between the disperse intra-enteral type of the hagfish and the compact extra-enteral type of other vertebrates.Erythrocytes are formed in the spleen pulp, granulocytes in the granulocytopoietic organ of the intestine and in the capsules of kidneys, gonads, and spleen. Thrombocytes and monocytes are differentiated in the spleen and general circulation. Basophils arise in the spleen and intestine. Lymphoid cells of all types arise in the spleen. Evidence is presented bearing upon the hemocytopoietic capacity of the various types. Cells with [Russell bodies] also occur in the spleen.In lungfishes subjected to long periods of dry estivation, erythrocytopoiesis practically ceases. Granulocytes, however, appear to play an important rǒle, possibly in fat metabolism. The large variety of meta-eosinophils, a unique feature of the lungfish, appears to be associated with the habit of estivation.Recovery from estivation may show numerous amitoses of erythrocytes in the general circulation. Other cells which divide in this manner are young thrombocytes, granulocytes, monocytes, and lymphoid hemoblasts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1050510203
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  • 4
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    Notes on the postnuclear, acrosome-seat granules, and ‘vacuome’ in Desmognathus fusca spermatogenesis (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 51 (1931), S. 597-612 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The acrosome in Desmognathus, Spelerpes, Plethodon, salamander, Amphiuma, etc., is attached to the nucleus in connection with an acrosome seat, which forms a shallow cup, traced back to a number of granules in the early spermatid. A postnuclear plate is present in the above-mentioned urodeles, and is derived from a small number of minute granules which assemble in the spermatid and become fixed onto the nuclear membrane. The centrosomes of the spermatid are visible intravitam. The ‘vacuome’ is formed of minute neutral-red-staining globules embedded in the idiozome. No connection appears to exist between mitochondria and Golgi bodies, as is postulated by the vacuome-chondriome hypothesis (Parat).
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1050510209
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  • 5
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    Studies on the comparative histology of the digestive tube of certain teleost fishes II. A minnow (Campostoma anomalum)Studies from the Department of Zoölogy, The University of Nebraska, no. 168. (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 52 (1931), S. 1-25 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This paper presents a study of the normal histology of the digestive tract of an herbivorous teleost, the minnow Campostoma anomalum (Raflnesque). The tunics of the buccal cavity, pharynx, esophagus, and intestine are described; particular attention is given to the mucosa because of the specializations occurring in that coat, such as taste buds, goblet cells, callous pad, etc. Because of the very decided anatomical and histological differences existing between the anterior and posterior regions of the pharynx, due to the presence of a callous pad and pharyngeal teeth, it has been deemed advisable to consider the pharynx as divisible into an anterior and a posterior region. Thyroid tissue was found in the submucosa of the anterior pharynx. No gastric epithelium was demonstrated, the ‘intestinal bulb,’ the only enlargement of the coelomic portion of the digestive tube, being lined with epithelium presenting only minor differences from that found in the coiled tubular intestine.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1050520102
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  • 6
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    Visceral anatomy of the amphisbaenia (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 163 (1980), S. 99-133 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Study of the visceral anatomy of 41 specimens of amphisbaenians representing 13 genera shows that they share a very distinct structure which differs from that found in either snakes or typical lizards. The left lung is large while the right is rudimentary or absent (unique); the kidneys are freely suspended in the coelom by a mesentery (unique); the spleen is usually embedded in the anterior end of the pancreas (as in snakes); the gall bladder lies in a notch in the liver, and the kidneys lie opposite each other (as in lizards). The distinctness of this pattern supports the recognition of the Amphisbaenia as a separate suborder of the Squamata.
    Additional Material: 28 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051630202
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  • 7
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    Cytodifferentiation and vitellogenesis during oogenesis in arachnida: Cytological studies on developing oocytes of a harvestman (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 163 (1980), S. 175-190 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Light and electron microscope studies were made on harvestman oocytes during the course of their origin, differentiation, and vitellogenesis. The germ cells appear to originate from the ovarian epithelium. They subsequently migrate to the outer surface of the epithelium, where they remain attached often by means of stalk cells which suspend them in the hemocoel during oogenesis. The “Balbiani bodies,” “yolk nuclei,” or “nuage” constitute a prominent feature of young, previtellogenic oocytes, and take the form of large, but variable sizes of electron-dense cytoplasmic aggregates with small fibrogranular components. The cytoplasmic aggregates fragment and disperse, and cannot be detected in vitellogenic oocytes. The young oocytes become surrounded by a vitelline envelope that appears to represent a secretory product of the oocyte. The previtellogenic oocytes are impermeable to horseradish peroxidase under both in vivo and in vitro conditions. In addition to mitochondria, dictyosomes, and abundant ribosomes, the ooplasm of the previtellogenic oocyte acquires both vesicular and lamellar forms of the rough-surfaced endoplasmic reticulum. In many areas, a dense homogeneous product appears within the cisternae of the endoplasmic reticulum and represents nascent yolk protein synthesized by the oocyte during early stages of vitellogenesis. Later in vitellogenesis, the oocyte becomes permeable to horseradish peroxidase under both in vivo and in vitro conditions. This change is associated with a massive process of micropinocytosis which is reflected in the presence of large numbers of vesicles of variable form and structure in the cortical ooplasm. Both spherical and tubular vesicles are present, as are coated and uncoated vesicles. Stages in the fusion of the vesicles with each other and with developing yolk platelets are illustrated. In the harvester oocytes, vitellogenesis is a process that involves both autosynthetic and heterosynthetic mechanisms.
    Additional Material: 32 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051630206
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  • 8
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    Ultrastructural study on cocoon formation in the freshwater oligochaete, Tubifex hattai (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 164 (1980), S. 25-38 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The clitellar epithelium of the freshwater oligochaete, Tubifex hattai, is composed of four types of gland cells (Type I, II, III, and IV), in addition to the cells generally found in the epidermis of this worm. The possible function of these gland cells in cocoon formation was studied with the electron microscope.Type I cells discharge their secretory granules by means of compound exocytosis and provide the materials for the future cocoon membrane. Immediately after completion of the discharge from Type I cells, Type II and III cells simultaneously discharge their secretory granules by means of compound exocytosis. The secretions from Type II cells constitute a colloid in the cocoon lumen and probably cause structural modifications in the future cocoon membrane. The secretory products from Type III cells form the cocoon plug. Although the process of discharge of secretory granules from Type IV cells was not observed, the contribution of these cells to the cocoon formation, producing hoops on the outer surface of the future cocoon membrane and fixing its anterior ends on the clitellum, is inferred from a morphological comparison of the hoop and the structure of the secretory granules.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051640103
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  • 9
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    The distribution of monoamine oxidase and biogenic monoamines in the central nervous system of spiders (Arachnida: Araneida) (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 164 (1980), S. 69-81 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The distribution and activity patterns of monoamine oxidase and monoaminergic (formaldehyde-induced) fluorescence in the central nervous system of web-building and hunting spiders have been studied using histochemical methods. Enzyme activity occurred in the neuronal perikarya and in varying intensity in the structures of the neuropile mass, but only when dopamine, adrenaline, and noradrenaline were used as substrates. The optic centres of the spider brain normally exhibited relatively strong enzyme reactions when compared with the staining intensity of the rest of the nervous system.The neuronal cell bodies contained numerous granules of yellow-green fluorescence. Monoaminergic fluorescence of the neuropile was generally a weak green. The optic mases of the hunting spiders, the anterior bridge, several commissures of the ventral cord, and the neural lamellae showed a slightly higher fluorescence intensity and single fluorescing granules.The results obtained indicate the presence of catecholamines in the spider nervous system.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051640106
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  • 10
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    Formation of the pits with taste buds at the lingual root in the striped dolphin, Stenella coeruleoalba (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 164 (1980), S. 107-119 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The tongue of the striped dolphin, Stenella coeruleoalba, shows a V-shaped row of pits on its posterior dorsum. Their development is described on the basis of macroscopic and light microscopic observations on fetal, young, and adult stages. Four to eight pits occur, most often five in the adult. Anlagen of the pits first protrude as round epithelial thickenings which later increase in diameter and become thin. The circular primordia then sink, and grooves oriented both circularly and radially develop in the walls of the shallow pits thus formed. Pits and grooves deepen with development so that older pits become lined with conical projections. As pits grow further, they become elongated anterolaterally, retaining slit-like openings. Each pit in the adult is 2-8 mm long and about 1 mm wide. The pits are not derived from lingual gland ducts but develop independently. Taste buds resembling those of other mammalian tongues can be found in young dolphins but are few in number and limited to the thin epithelium of the pit projections and to that of the side wall of the pits. They first appear in the late prenatal period but degenerate in the adult. A rich nerve supply is observable in the lamina propria below taste buds in the calf. The pits and their projections in the dolphin correspond to the vallate papillae of other mammals, but whether each projection or a whole pit corresponds to a single vallate papilla is undecided.
    Additional Material: 22 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051640202
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  • 11
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    Fine structure and distribution of epidermal projections associated with taste buds on the oral papillae in some loricariid catfishes (Siluroidei: Loricariidae) (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 164 (1980), S. 139-159 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Two morphologically distinct structures occur on the surfaces of the oral papillae in several loricariid catfish species; namely, (1) typical vertebrate taste buds composed of receptor and sustentacular cells and (2) brushlike projections, termed epidermal brushes, that represent specialized epidermal cells containing keratin. Both of these structures were studied with the combined use of light microscopy and scanning and transmission electron microscopy. The general body surface, fins, and rostral cutaneous processes of some loricariid catfishes are covered with taste or terminal buds but lack the epidermal brushes. It is suggested that the epidermal brushes found on the oral papillae serve as protective devices for the taste buds and as abrasive surfaces for substrate scraping during feeding. The taste buds on the oral papillae may detect any gustatory stimuli from the resulting substrate disturbance. Comparative studies reveal many differences in the number and spatial arrangement of these two structures on the oral papillae among the several species of the Loricariidae examined. These differences may represent functional adaptations to the various modes of life in the Loricariidae.
    Additional Material: 36 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051640204
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  • 12
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    Identification of the Y-organ in the larval stages of the crab, Cancer anthonyi Rathbun (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 164 (1980), S. 83-88 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The Y-organ has been histologically identified in all six larval stages of the crab, Cancer anthonyi. The paired glands are located anterior to the branchial chamber and ventral to the base of the antennules. In the first zoeal stage the gland consists of a cord of 6 to 10 epidermal cells with dark staining nuclei, sparse cytoplasm, and indistinct cell boundaries. As development progresses the glands become more complex through extensive folding and intertwining of the cellular cords. The glands in all larval stages show cyclical activity which corresponds to the molt cycle. Immediately following a molt the gland is dense and compact with little cytoplasm. At approximately day four in the molt cycle, the glands become greatly hyperthropied due to an increase in the number and size of the cytoplasmic vacuoles. These histological changes suggests a cyclical production and presumably the release of some product most likely ecdysone.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051640107
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  • 13
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    The morphology of a harpacticoid copepod gut: A review and synthesis (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 164 (1980), S. 89-105 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The digestive tract of a harpacticoid copepod, Tigriopus californicus (Baker), was studied by using techniques of light and electron microscopy. Four cell types could be distinguished: type 1, an embryonic cell which will replace cells worn away or lost during secretion; type 2, a cell which synthesizes and secretes proteins and also plays a role in lipid absorption; and types 3 and 4, two cell types which absorb lipids. From the abundance of each cell type, the length of microvilli, the development of basal plasma membrane (PM), and luminal projections, the following conclusions were made. (1) The midgut caecum absorbs digested nutrients. (2) The anterior midgut absorbs nutrients and more importantly functions in merocrine and exocrine secretion. The presence of concretions in cell types 2 and 3 in the anterior midgut suggests that these tissues contribute in excretion, and in water and/or ion regulation. (3) The posterior midgut absorbs nutrients and contributes some holocrine secretion.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051640108
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  • 14
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    Sense organs on the antennal flagellum of the human louse, Pediculus humanus (Anoplura) (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 164 (1980), S. 161-166 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Tactile hairs are present on all three subsegments of the antennal flagellum of the human louse. There is, in addition, a single chemoreceptor (tuft organ) on subsegment 2 and 12 or 13 chemoreceptors (one tuft organ, two pore organs and nine or ten pegs) on subsegment 3. The cuticle surrounding the bases of the pegs at the tip of the antenna is unusual in that parts of it are perforated by many fine pores. This cuticle is underlain by a thin layer of dendrites. This region may also have a chemoreceptor function.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051640205
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    An electron microscopic study of hemoglobin synthesis in the marine annelid, Amphitrite ornata (Polychaeta: Terebellidae) (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 164 (1980), S. 121-138 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The heart-body of the marine worm Amphitrite, located within the supraesophageal dorsal vessel, is in the form of a cylinder the thin wall of which is deeply corrugated by luminal projections and folds along its entire length. It is anchored in places to the luminal surface of the dorsal vessel by an extracellular matrix containing collagen fibers. The luminal surfaces of both the heart-body and the dorsal vessel are covered by a basement membrane-like vascular lamina which in turn supports a discontinuous pseudoendothelium of littoral hemocytes.The cells of the heart-body constitute a pseudostratified, high columnar epithelium. They possess extensive rough endoplasmic reticulum (RER), a well developed Golgi zone, ferritin particles and granules, and several types of membrane-bound inclusions. Hemoglobin molecules identical to those in the circulation lie within cytoplasmic, membrane-bound vesicles. Analysis of our electron micrographs suggests the following sequence of hemoglobin production and secretion: Large quantities of a moderately dense flocculent material, probably globin, are synthesized in RER and move to the Golgi zone within partly rough- and partly smooth-surfaced transitional cisternae; small transport vesicles, formed from Golgi cisternae that have fused with transitional cisternae, convey the flocculent material from the convex to the concave face of the Golgi complex; a similar flocculent material and an amorphous, highly dense material are processed in the Golgi complex and are transferred to condensing vacuoles in which clearly identifiable hemoglobin molecules are first observed. Mature secretory vesicles containing only hemoglobin migrate to the cell periphery and discharge their contents by exocytosis. Hemoglobin molecules then cross the vascular lamina to reach the circulation.
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    URL: http://dx.doi.org/10.1002/jmor.1051640203
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    The auditory region of dermoptera: Morphology and function relative to other living mammals (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 164 (1980), S. 167-211 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The dermopteran basicranium combines a primitively constructed and oriented auditory bulla formed by ectotympanic, rostral entotympanic, and tubal cartilage with derived features of the middle ear transformer and internal carotid circulation. Living dermopterans possess a primitive eutherian auditory region that has been structurally modified to perceive a lower frequency sound spectrum than probably was utilized by ancestral Mesozoic therians. Perception of the low to midfrequency range is enhanced in Dermoptera by reducing stiffness in the mechanical transformer while maintaining low mass of the component parts. Stiffness has been reduced by (1) development of an epitympanic sinus about four times the volume of the middle ear cavity proper, (2) detachment of the anterior process of the malleus from the ectotympanic, and (3) by delicate suspension of the ear ossicles within the middle ear.We apply to dermopterans a measure of hearing efficiency derived from recent functional studies of the mammalian middle ear that regards the middle ear mechanism as an impedance matching transformer. Calculation of the impedance transformer ratio for Dermoptera suggests that these mammals are relatively efficient in comparison to other eutherians in their ability to match the impedance of cochlear fluids to that of air at the eardrum. Dermopterans theoretically are capable of using over 90% of incident sound energy striking the eardrum at the resonant or natural frequency. Mechanical impedance of the middle ear transformer exerts a minimal influence on hearing efficiency due to low mass, little stiffness, and little frictional resistance.Analysis of measurements of the middle ear transformer published by Gerald Fleischer and integration of these data with current theory on the peripheral hearing mechanism in mammals allow us to propose a model that describes the structural and functional evolution of the mammalian middle ear transformer. Structural changes appear to be correlated with alteration in function from primitive small mammals with stiff middle ear transformers and high frequency dominated hearing to mammals with a wider range in body size with more mobile middle ear transformers and a greater range of frequency perception, often including improved sensitivity to lower frequencies.Mammals employ different anatomical strategies in attainment of increased hearing efficiency and sensitivity. Efficiency is improved by adjustment of lever and areal ratios of the middle ear transformer to achieve an optimum impedance match of external air and cochlear fluids. Sensitivity over a broad frequency spectrum is attained by minimizing mass, stiffness, and frictional resistance of the transformer. The morphology of the auditory region of both living and fossil mammals seems explicable in terms of selection pressure directed toward these ends.
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    URL: http://dx.doi.org/10.1002/jmor.1051640206
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    Announcement (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 164 (1980), S. 311-311 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051640307
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  • 18
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    Gross structure and function of the quadriceps femoris in Lemur fulvus: An analysis based on telemetered ElectromyographyForce plate data on a wide variety of nonhuman primates (Kimura et al., '79) indicate that, in comparison to other mammalian quadrupeds (e.g., cats), virtually all primates are somewhat hindlimb dominated; i.e., the vertical and propelling peak component of force is consistently larger in the hindlimb than in the forelimb. The forelimbs of those species examined tend to act primarily to brake the body. (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 164 (1980), S. 287-299 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Analysis based on telemetered electromyography from the quadriceps femoris of Lemur fulvus, a Malagasy prosimian, during walking, galloping, leaping, and a variety of postural behaviors partially confirms and partially contradicts earlier hypothesized functions of this musculoskeletal complex. As predicted on the basis of morphological criteria (large physiological cross-section and long parallel fibers), the vastus lateralis is of special functional significance in leaping. This relatively large muscle consistently initiates the leap and frequently undergoes a very long period of force enhancement via active stretch. By contrast, the vastus intermedius fails to exhibit increased electrical activity and undergoes little or no active stretch during jumps. The myological details of vastus intermedius (short fibers, no fusion with other components), therefore, cannot be accounted for as adaptations to leaping. Rather, a primary postural role is indicated for the vastus intermedius, because in normal resting postures, with the knee quite flexed, it alone is continuously active. The existence of a fibrocartilaginous superior patella in the tendon of vastus intermedius, however, is most plausibly related to the complex tensile and compressive stresses generated in the tendon during the completely hyperflexed phase of leaping.The phasic patterning of the quadriceps femoris of Lemur fulvus does not point to any special role of the vastus lateralis or vastus intermedius during walking and galloping; it does indicate very different patterns of muscle recruitment in comparison to those in nonprimate mammals and some anthropoid primates. The forward cross walk (diagonal sequence, diagonal couplets) of primates versus the backward cross gait (lateral sequence) of most other mammals probably accounts for some of these differences. Lemur fulvus lacks the degree of elastic storage and release of kinetic energy in the quadriceps femoris that characterizes the gallop of dogs, cats, and Erythrocebus patas.
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    Time-lapse cinemicrographic studies of cell motility during morphogenesis of the embryonic yolk sac of Fundulus heteroclitus (Pisces: Teleosti) (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 165 (1980), S. 13-29 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The active motility of the cells of the yolk sac of the living Fundulus embryo was studied by time-lapse cinemicrography with phase contrast optics. In the teleost, the yolk sac lies peripheral to the body of the embryo proper and consists of a fluid-filled space bounded above by a superficial epithelium, the enveloping layer (EVL), and below by the yolk syncytial layer (YSL). The cell types treated in the present study are the enveloping layer epithelial cell, the stellate cell which lies in a layer flattened on the inner surface of the EVL, the epithelioid deep cell, the yolk sac amoebocyte, the yolk sac endothelial cell and the yolk sac melanoblast. The most actively motile cells examined in the present study are the yolk sac amebocyte and the melanoblast, which emigrates from the embryo proper at stages 19-21. The amoebocytes are compact rounded cells that move very rapidly by the extension of lamellipods with scalloped margins. The amoebocytes wander over the yolk sac in an apparently undirected fashion and invade the embryo proper when they happen to encounter it, moving between cells of the lateral mesoderm. The melanoblasts migrate by the gradual extension of elongated branching processes. Cells are sometimes monopodial, with movement being parallel to the long axis of the cell. Alternatively, movement may be perpendicular to the predominant long axis, with processes being extended alternatively from opposite ends of the cell obliquely forward, so the path described is a zig-zag to either side of the overall direction of movement. Although the melanoblasts show irregularity in their movement, the predominant direction of initial movement is away from the embryo proper. The major yolk sac blood vessels form in situ by the collective activities of presumptive endothelial cells that enclose volumes of the yolk sac space with sheet-like processes from the cell body and from the extensions that connect cells into networks.
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    Masthead (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 165 (1980) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051650201
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    Morphometrics of the skeleton of Dermophis mexicanus (Amphibia: Gymnophiona). Part I. The vertebrae, with comparisons to other species (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 165 (1980), S. 117-130 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Morphometric analysis of vertebral structure in caecilians (Amphibia: Gymnophiona) is presented. Ontogenetic variation in Dermophis mexicanus is analyzed through the 100+ vertebrae composing the column. Vertebral structure in adult D. mexicanus is compared with that in Ichthyophis glutinosus and Typhlonectes compressicauda. Centra of the atlas, second, tenth, 20th, and 50th vertebrae grow at allometrically different rates in D. mexicanus, though the 20th and 50th are not significantly different, Growth appears significantly slower in several dimensions of anterior and posterior vertebrae relative to midtrunk vertebrae in all three species. Mensural patterns throughout the entire column are similar in the terrestrial burrowers D. mexicanus and I. glutinosus; patterns in the aquatic T. compressicauda differ substantially from those of the burrowing species and are strongly influenced by allometry. Of the 112 D. mexicanus examined, 13.4% had vertebral anomalies, usually fusions.
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    Comparative studies on the statoblasts of higher phylactolaemate bryozoans (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 165 (1980), S. 131-155 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Statoblasts of five higher phylactolaemates were compared morphologically. As a result, they were divided into two groups: Group I comprising Lophopus crystallinus, Lophopodella carteri, and Pectinatella gelatinosa, and Group II comprising Pectinatella magnifica and Cristatella mucedo. These two groups are thought to represent independent evolutionary series. In Group I and in P. magnifica, the statoblasts are curved to varying degrees after the manner of a saddle. When the dorsal and ventral valves are flattened, therefore, the contour is different between the two. In Group I, the outermost layer of a mature statoblast is hard-gelatinous and basophilic; it remains intact after the statoblast is set free. The statoblast does not float until it is dry, and the float is similar in size on both valves. In Group II, a mature statoblast is covered by a softgelatinous basophilic layer, which decays after the statoblast is released. The statoblast floats without drying, and the float is better developed on the dorsal valve than on the ventral. Moreover, in the members of Group II, large yolk granules are first formed, followed by much smaller yolk granules. When their statoblasts are treated with KOH, the shell is separated completely into two valves. These characters are common to many lower phylactolaemates. By contrast, in L. carteri and P. gelatinosa, the yolk granules are uniformly small and the capsule proper resists KOH treatment. On these points, L. crystallinus is somewhat different from these two species, suggesting its primitive nature.
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    Fetal tooth development and adult replacement in Dermophis mexicanus (Amphibia: Gymnophiona): Fields versus clones (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 166 (1980), S. 203-216 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Teeth of fetuses of a caecilian, Dermophis mexicanus (Amphibia: Gymnophiona), show ontogenetic variation in crown structure from small, multidenticulate, and non-pedicellate to larger, spoon-shaped, pedicellate teeth with a single apical spike. Number of denticles decreases as enamel-secreting cells mature. Numbers of teeth and of tooth rows increase ontogenetically. A fetal vomeropalatine set of teeth is present in D. mexicanus but absent in species previously examined. Teeth transitional to the adult shape and arrangement appear shortly before birth. The transition is correlated with birth, not fetal size. There is relatively little increase in numbers of teeth during the juvenile period. The pattern of development does not fully agree with either morphogenetic field theory or with clone theory, both as defined by Osborn ('78). Sequence of initiation is appropriate to either. Tooth shape changes agree with aspects of clone theory. Multiple rows of fetal teeth and the transition to adult follow field theory. Clone theory holds that patterns of development and shape are self-regulated, field theory that they are controlled extrinsically. I suggest that substances regulating differentiation mediate early development, and hormones later development, including inception of adult teeth, and are comparable to “field substances” influencing primordia that originate according to clone theory. Components of both theories are appropriate to analyzing tooth development phenomena.
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    Masthead (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 166 (1980) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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    URL: http://dx.doi.org/10.1002/jmor.1051660301
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    Pheromone glands of microcaddisflies, (Trichoptera: Hydroptilidae)Journal paper no. 925. Montana Agricultural Experimental Station. (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 163 (1980), S. 9-12 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Previously unreported structures found on the head and thorax of several species of microcaddisflies (Trichoptera: Hydroptilidae) are described. Depending on the species, these presumptive pheromone-producing glands are found either (1) on the basal segment of the antenna, (2) on movable and immovable occipital sclerites, (3) as eversible organs from the occipital area of the head, or (4) on structures which are attached near the bases of the front wings.
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    The morphology of dermal chromatophores in the infrared-reflecting glass-frog Centrolenella fleischmanni (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 163 (1980), S. 37-44 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The morphology and organization of chromatophores in the neotropical glass-frog, Centrolenella fleischmanni (family Centrolenidae), were studied with both light and electron microscopes. Four types of pigment cells are described in the dorsal skin. The fine structure of two chromatophores corresponds to the typical amphibian xanthophore and iridophore; one is similar to the unusual melanophore found in phyllomedusine hylids; the fourth cell type is unlike any chromatophore previously described. Pigment granules in the unusual chromatophore are moderately electron-dense and have an irregular shape, suggesting a fluid composition. This pigment appears to be laid down in organelles similar in appearance to pterinosomes. The organization of pigment cells in this species differs from that of other green, leaf-sitting frogs in that there are few discrete groups resembling “dermal chromatophore units.” It is suggested that the unusual new pigment cell contributes significantly to the overall green color of C. fleischmanni.
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    Masthead (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 163 (1980) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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    URL: http://dx.doi.org/10.1002/jmor.1051630201
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    Intralamellar neurohemal complexes in the cerebral commissure of the leech Macrobdella decora (Say, 1824): An electron microscope study (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 163 (1980), S. 157-165 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Electron microscopy of the cerebral ganglionic commissure of the leech Macrobdella decora (Say, 1824) revealed numerous neurosecretory axons terminating in the neural lamella of both the inner and outer capsules, and in the neural lamella deep within the neuropile. The proximal protions of the terminals, with an investment of glial tissue, contain either numerous large homogeneously electron dense granules, or numerous large granules of varying electron density. The distal portions, often devoid of glia, display numerous infoldings, omega profiles, and electron dense focal sites, and contain numerous neurosecretory granules, small lucent vesicles, and, occasionally, acanthosomes. Statistical analysis of the size distribution and morphology of the neurosecretory granules showed that in many individual terminals the granules are not significantly different from those seen within four groups of neurosecretory cells found in the cerebral ganglion. These terminals, because of their diffuse nature, probably represent a neurohemal complex of a primitive nature. The term “intralamellar complexes” is proposed to describe the form and location of these neurosecretory terminals.
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    Masthead (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 163 (1980) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051630301
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    The secretory response in dissociated acini from the rat submandibular gland (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 163 (1980), S. 219-230 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Rat submandibular gland was dissociated by enzymatic digestion with collagenase and hyaluronidase, followed by mild mechanical shearing and filtration through a nylon mesh. The dissociated cell populations contained predominantly groups of acinar cells which maintained their acinar arrangement. The morphological and functional viability of the cells was confirmed by electron microscopic examination and a normal secretory response to β-adrenergic or cholinergic stimulation was observed. Both isoproterenol (IPR) and carbachol caused the fusion of secretory granules into large vacuoles which were also continuous with the lumen, and into which the secretory product was released. Secretion was assessed quantitatively from the incorporation of 14C-glucosamine into the acinar cells and its subsequent release into the culture medium as labelled glycoprotein. IPR stimulated secretion to 125% of untreated controls in the concentration range 5 × 10-5 to 5 × 10-7 M, and to 110% of controls at 5 × 10-8 M, after 40 min incubation. Carbachol stimulated secretion to 131% of controls at 5 × 10-5 M and to 115% at 5 × 10-6 M but had no effect at 5 × 10-7 or 5 × 10-8 M. The secretory response was blocked by the respective β-adrenergic and cholinergic antagonists, propranolol and atropine. These findings show that dissociated rat submandibular acinar cells provide a useful in vitro model for the study of mucus synthesis and secretion.
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    The history of the germ cells in the viviparous teleost platypoecilus maculatus (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 52 (1931), S. 115-153 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This study is based upon a series of ontogenetic stages from just before coelom formation to maturity.Primordial germ ceils are first seen at the outer edge of the lateral mesoderm and are traced from there to a position in the genital analagen. Counts indicate that most of them succeed in reaching the genital anlagen, where they from definitive reproductive cells in both sexes.The evidence seems to show that there is some transformation of somatic cells into germ cells in the immature female, but that this transformation is not extensive. In the male the primordial germ cells are the sole source of the definitive elements.
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    The development of the carp, cyprinus carpio. I. The larval life of the carp, with special reference to the development of the intestinal canal (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 52 (1931), S. 217-231 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The detailed spawning habits and hatching period are described. The larval period is divided into the inactive, when the yolk is the source of food, and the active period, when food is captured. The rate of growth and transformation of the larvae into fry is described.The cell formation passes into a syncytial period, when there are produced many nuclei without cytoplasm.c division. Around these nuclei, the cytoplasm collects to give rise to more cells. The method by which mucous cells are produced is described and also the presence of secretion masses in both the mucous cells and the syncytium of the mucosa.
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    The development and the regeneration of the color pattern in brachydanio rerio (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 52 (1931), S. 513-523 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The teleost fish Brachydanio rerio is strikingly marked with longitudinal black stripes, which extend into the caudal fin and across the anal fin. Removal of the anal fin is followed by complete regeneration of the fin and of its normal color pattern. Microphotographic studies show that melanophores are at first uniformly distributed in the regenerating tissue and that later the melanophores disintegrate in the zone of the future light stripe and increase in the region of the future dark stripe. Observations on the normal development of the fin where the history of the individual melanophores has been followed show the same mode of formation of the stripes.
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    Masthead (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 51 (1931) 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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    URL: http://dx.doi.org/10.1002/jmor.1050510101
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    History of the germ cells in Sphaerium striatinum (Lam.) (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 51 (1931), S. 545-595 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Study of living and sectioned material throughout the life cycle shows the germ-cell history from fertilized egg to sexual maturity. This can be divided into the following five periods with definite limits: Original appearance during cleavage, period of inactivity, period of multiplication, maturation, and fertilization. Primordial germ cells of characteristic structure can be recognized just before gastrulation, when there is one large germ cell in the mass of mesoderm on either side of the blastocoel. After one division in each of these two cells, the four daughter cells remain inactive, while the remainder of the mesoderm differentiates, until division is resumed in the developing gonad. An indefinite number of gametes is produced. All are direct descendants of the two original primordial germ cells. Transformation of somatic cells into germ cells does not occur nor do germ cells become somatic cells. Cell lineage shows the two primordial germ cells to be derived from the third division of the paired mesoderm cells which have arisen by an equal division of the fourth micromere produced by cell D of the four-cell stage. Details of meiosis have not been ascertained, because of the small size of the chromosomes, their large number, and the difficulty of fixation. Nothing forecasts which primordial germ cells will become ova and which spermatozoa.
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    Cytoplasmic structures in binucleate opalinids, with special reference to the Golgi apparatusThis investigation was carried out with the aid of the Cancer Research and Treatment Fund. (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 52 (1931), S. 27-45 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Three types of cell inclusions are demonstrated within the general protoplasm of the binucleated Protoplina, parasites of Hyla aurea. These are considered to represent mitochondria, together with associated, synthesized vegetative granules and Golgi bodies, as evidenced by their behavior, morphology, and staining reactions.The Golgi material is shown to consist of irregularly twisted rods and granules scattered at random in the cytoplasm, but possessing a very distinctive morphology and reaction to different techniques when compared with the mitochondria. No relationship could be detected between these vegetative structures and the cilia, as has been previously described.These observations have also been extended to a similar study of the cytoplasmic organs of Nyctotherus cordiformis, and it has been possible to demonstrate Golgi bodies of a similar appearance within this organism as well as to show again the nature of the basal granules and their relationship to the cilia.The procedure of identifying the mitochondria elements with great care is recommended as a preliminary means of studying the Golgi apparatus of Protozoa, particularly where osmication techniques are used exclusively.
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    The intranuclear deutoplsmThe terms deutoplasm and yolk are used in this paper, as they seem to be generally used by turbellarian workers, to denote material that is used as food material by the developing organism and which, with ordinary stains and technique, reacts like yolk. It should be understood that no specific chemical tests for yolk have been empolyed in this work. and the origin of gametes in the turbellarian Prorhynchus applanatus Kennel (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 52 (1931), S. 233-247 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: It is shown that in Prorhynchus applanatus there exists a type of yolk elaboration which has hitherto not been reported. Formation is within the nucleus through the growth and fusion of nucleoli, but the yolk globule becomes larger than the original nucleolus. The developing individual utilizes the food material contained in the yolk cells in the following order: (1) cytoplasm of the yolk cell, (2) yolk bodies contained in this cytoplasm, (3) intranuclear yolk, (4) nucleoplasm. It is also shown that the germ cells in this form arise from the endoderm by diapedesis, but that the yolk cells are mesenchymal in origin. The sequence of formation of male and female gametes precludes the possibility of the presence of sex hormones such as are found in higher forms.
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    A comparative study of the chromosomes of rodentsContribution from the Department of Zoölogy, University of Texas. This work was done under the direction of Dr. T. S. Painter, to whom the writer wishes to express his obligation and appreciation. (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 52 (1931), S. 373-401 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A comparative study has been made of fifteen species and subspecies of rodents to determine the range in number and variation in morphology of their chromosomes. The number range is between 40 and 86±, with an average number for known species of 52. In the family of Cricetidae there is little variation in chromosome number and a general similarity of the chromosomes. In the Muridae the range for known species is 40 to 42, but the chromosome morphology even of subspecies may be quite different. In Sciuridae a range of 48 to 62 has been found in different species. The greatest range in number is found in the Heteromyidae, 44 and 86± chromosomes having been found in two species. It is concluded that the stem number for rodents is close to 48 and that fragmentation and fusion account for variation in numbers, and these affect the morphology of the chromosomes. The evidence also indicates that variations in morphology are due to translocations and inversions, and possibly deletions accompanied by translocations.
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    The distribution of sperm-forming materials in scorpions (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 52 (1931), S. 429-483 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: There are in scorpions two sharply contrasting types in respect to the mode of distribution of the chondriosomes to the sperm cells. In one of these the chondriosomes, spheroidal in form and nearly definite in number, are sorted out whole without division during the spermatocyte divisions, their number being thus reduced successively to one-half and one-fourth. This type occurs in Opisthacanthus, Hadrurus, Vejovis, Euscorpius, and Palamnaeus. In the other, as yet known only in Centrurus, all the chondriosomes fuse during the spermatocyte growth period to form a single ring-shaped body; and this, during the two ensuing mitoses, is accurately divided into two, four, and eight equal parts, of which each spermatid receives two. In both types alike the chondrioma is thus distributed very nearly equally to the sperm cells, but by widely contrasting processes; and in both types the spermatid chondriosomes are drawn out to form the sheath of the axial filament in the sperm tail. In Opisthacanthus there are indications of a definite process of dictyokinesis during the spermatocyte divisions.These facts are discussed in the light of the general history of the chondriosomes in other animals, with especial reference to more general problems of cell division. The present vagueness and uncertainty of our knowledge of cell division and differentiation are emphasized.
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    Polymorphism among the subgenera of nasutitermes (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 52 (1931), S. 593-607 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This study is concerned with the interrelationship existing among the polymorphie soldier castes of six representative subgenera of the genus Nasutitermes. By measurements of anatomical parts and camera-lucida drawings, an attempt has been made to compare these particular subgenera on a basis of gradual divergence of certain structures. For this purpose a series of tables was compiled in which apparently unstable structures were compared to a relatively stable figure in all available species of the selected subgenera.According to my findings, it was concluded that there is no strict correspondence between the major, intermediate, and minor castes of different subgenera of the genus Nasutitermes. Particular reference is made to the work of N. Holmgren ('12) and to that of J. S. Huxley on heterogonic growth.
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    The distribution of the branchial nerve in Mytilus edulis and its relation to the problem of nervous control of ciliary activity (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 51 (1931), S. 195-205 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The branchial nerve of Mytilus edulis, traced by means of serial sections, has been found to be limited entirely to the epithelial and connective tissues bordering the axis of the gills. Most of the numerous branches which originate from the branchial nerve extend posteriorly and lie close to the interfibrillar matrix of the connective tissue which supports the epithelium of this region. Fibers of these nerves have been traced to this epithelium.The chitinous supporting structures of the gills lie in close proximity to these nerves, yet neither nerves nor nerve fibers have been observed to penetrate them. Moreover, a careful study of the gill tissues fails to reveal the presence of structures which might be interpreted as nerves or nerve fibers.Since no innervation of the gills has been demonstrated, it seems probable that the ciliary activity of the gill epithelium is not regulated by means of fibers connected with the central nervous system.
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    The morphology of Spironympha, with a description of a new species from reticulitermes hesperus Banks (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 51 (1931), S. 291-307 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Spironympha is discussed as valid genus. It was described by Koidzumi ('16); later it was redescribed by the same author as Microspironympha ('21). Therefore, according to the rules of nomenclature, it is Spironympha.The genus is compared with the related genera: Spirotrichonympha, Holomastigotes, and Microjoenia.Spironympha is characterized by four flagellar bands which are spirally wound around the anterior part of the body; these bands occur only in the anterior end, whereas in Spirotrichonympha they extend almost to the posterior end. The parabasals are few in number, and they are attached to the basal granules of the flagellar bands; the anterior end is clear and almost free from cytoplasmic granules; and there are twenty to thirty anterior flagella which are attached to the base of the centroblepharoplast or to the basal granules of the flagellar bands. An axostyle is present.No centrosome occurs within the nucleus, but the centroblepharoplast has this kinetic function.Spironympha ovalis is described as a new species. It is ovoid; the average size is 38 μ to 44 μ. An axostyle is present. The host is Reticulitermes hesperus Banks.
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    The embryogeny of the Polyctenid, Hesperoctenes fumarius Westwood, with reference to viviparity in insects (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 51 (1931), S. 1-117 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Four functional types of viviparity are recognized, and the last, pseudoplacento viviparity, is illustrated by a review of the embryogeny of a species of Polyctenidae. This insect normally has ten embryos in the reproductive tract in successive stages of development. The problem of fertilization is discussed, for there seems to be no spermatheca and spermatic clumps are present in the haemocoel. No organ of Berlese can be found. One, apparently a nymph, when sectioned revealed spermatozoa in even greater abundance than the mature females. Four to six of her offspring would seem to be paedogenetic.Females liberate ova that are yolk-free, and no chorion is secreted about them. Blastomeres are distinct, the embryonic envelopes are formed as usual, and hemipteran embryology occurs. The trophserosa functions until blastokinesis takes place, when the pleuropodial extensions evaginate and encompass the embryo which now lies in a pleuropodial cavity. The pleuropodia function as Lutrient organs, or psedoplacenta, until shortly before birth. At birth the embryo is a little more than one-third the adult body length and bears strongly developed setae.
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    The labyrinth of bufo vulgaris japonicus larva. Especially, upon the morphologic study of the perilymphatic space, in connection with the membranous labyrinth and auditory capsule (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 51 (1931), S. 207-242 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A morphologic study of the labyrinth, especially on the perilymphatic space with its physiologic aspect, is presented in this paper. The perilymphatic space starts its development with the chondrification of the auditory capsule, and is completed by the end of the first third of metamorphosis. The author divides the whole spatium into two parts: the ductus perilymphaticus et diverticula and the pars spongiosa spati perilymphatici. The ductus perilymphaticus et diverticula may play an important rǒle in carrying out the functions of both equilibrium and audition. The pars spongiosa serves not only to fasten the membranous labyrinth to the capsular wall, but acts as a safeguard for the functions of both the membranous labyrinth and the ductus perilymphaticus et diverticula. The ductus system may have more important physiologic relations than does the membranous labyrinth in connection with the cranial cavity and spinal cord, as to the change of pressure, the transmission of vibrations, the osmosis of fluids, etc. A number of microscopic and schematic figures are shown with reference to the anatomic and morphologic relations of the membranous labyrinth, auditory capsule, and spatium perilymphaticum.
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    Observations on the ‘renal-portal’ perfusion in etherized birds (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 51 (1931), S. 309-318 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This investigation was made to demonstrate the direction of the current of a perfusing fluid (hence that of blood in nature) inside the so-called [renal-portal] vein of birds and to determine if this vein has any fine capillaries in the kidney substance. A domesticated male duck was anaesthetized with ether, and a warm saline (mixed with a little urea and urine) was passed through the aorta. The [renal-portal] vein was also perfused with the same fluid through the left internal iliac vein. At first the kidneys actively secreted semisolid urine, but gradually the strength of the latter varied from a milky to a watery fluid.Later, a warm carmine solution was perfused through the left internal iliac vein, and the path of the dye could be easily traced along the whole length of the left renal afferent (left [renal-portal] vein) and its final exit through the postcaval vein. The posterior lobe of the left kidney was partially tinged with red, probably due to diffusion, since the kidney substance should have taken a uniform red hue if there was any definite capillary system. The coccygeomesenteric vein contained no dye.These results (coupled with actual caliber measurements of the two [renal-portal] veins in duck and pigeon examined, the calibers of these veins increasing gradually posteroanteriorly) indicate that: 1) blood flows anteriorly in the [renal-portal] vein; 2) this vein does not break up into capillaries in the kidney substance, but receives larger affluent veins; 3) there is no [renal-portal] system in birds; 4) the urine secreted by birds is always semisolid.
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    Life cycle, sex differentiation, and testis development in Melanoplus differentialis (Acrididae, Orthoptera) (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 51 (1931), S. 467-525 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The general morphological and histological evidence accumulated by this study suggests the following facts: 1Under out-of-door conditions, in the vicinity of Philadelphia, Pennsylvania, embryonic development begins at deposition and continues to the middle or late spring, when hatching occurs. The postembryonic development is completed during the summer. Copulation and oviposition occur in the late summer and early fall.2The embryonic development may be divided as follows: aThe prerevolution period, in which the rudiments of organs and systems are formed.bThe early-revolution period, during which the direction of the embryo in the egg is reversed.cThe late-revolation period, or time of yolk circumcrescence and completion of the dorsal wall of the embryo.dThe postrevolution period. comprising development from yolk engulfment to hatching.3The sexes are differentiated during the early- and late-revolution periods.4In the differentiation of the genital rudiments, a) the germ cells are segregated into groups; b) and indifferent mesodermal element grows in among the germ cells of such a group; c) the processes of this cell (the apical cell) form intimate connections with the processes of connective-tissue elements surrounding the germ-cell group; and, d) the covering membrane of the genital rudiment grows in between the various germ-connective-tissue cell groups, completing the rudiment of the follicle.5When the adult condition is reached the testis is functionally differentiated.
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    The vacuome of the flagellate Chlamydomonas (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 51 (1931), S. 527-543 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A vacuome (‘Golgi apparatus’) consisting of small globular inclusions has been demonstrated in Chlamydomonas sp. These inclusions may be seen in the living, unstained organism; they are stainable vitally with neutral red; they have been stained vitally with neutral red and then blackened with osmic vapor under direct observation, and they have been impregnated by osmic and silver methods without previous treatment with neutral red.The reaction of these inclusions to the iodin test for starch suggests that they may play some rǒle, possibly one of storage, in the cycle of starch metabolism.
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    A scanning electron microscope study of the mesothoracic and metathoracic scolopophorous organs of Lethocerus (Belostomatidae-heteroptera) (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 163 (1980), S. 27-35 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The presence of scolopophorous organs in aquatic Heteroptera has been reported in a number of species. This study presents a morphological investigation of these sensory structures of Lethocerus (Belostomatidae) as observed with the scanning electron microscope (SEM). Paired mesothoracic and metathoracic organs are present. Externally, each sensory structure consists of a raised sensory membrane. The distal-most portion consists of thickenings of this sensory membrane (sclerite). The receptor neurons of the mesothoracic organ are of two types - one discolopidial sensillum and 12 monoscolopidial sensilla. The former is attached to the internal wall and distal thickening of the sensory membrane, while the latter are dispersed throughout the interior and attached to the internal wall of the sensory membrane. The structure of the organs suggest that an effective stimulus could be a compression of the membrane. A discussion of possible functions (pressure reception and hearing) is included.
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    Scanning electron microscopy and distribution of specialized mechanoreceptors in the texas rat snake, Elaphe obsoleta lindheimeri (Baird and Girard) (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 163 (1980), S. 59-67 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Scanning electron microscopy (SEM) of the surface tubercles of a specialized mechanoreceptor found within the head of Elaphe obsoleta lindheimeri indicates that the tubercle consists of a craterlike structure with a peg emerging from its center. After removal of the outer keratinized layers of the epidermis, the SEM discloses a replicate tubercle on the underlying alpha keratin layer. Over 6000 tubercles were found within a single snake. The mechanoreceptors were more densely concentrated on anterior scales, and their number appears to be species specific so that they are more concentrated in snakes with smaller heads than in those with larger ones.
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    Masthead (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 164 (1980) 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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    Hopping locomotion in a nematode: Functional anatomy of the caudal gland apparatus of Theristus caudasaliens sp. n. (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 164 (1980), S. 265-285 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The interstitial nematode Theristus caudasaliens n. sp. normally locomotes by hopping on the left side of its tail tip, a mode of locomotion that is unique among nematodes. The animal uses its caudal glands and caudal musculature to perform the hops, attaching itself momentarily between hops with the glands and executing the hops by straightening and curling the posterior part of its body.The caudal gland apparatus can be seen by electron microscopy to consist of five gland cells of two different types. Three of these cells, termed viscid glands, are involved in adhesion of the animal to substrates and produce ovoid granules with a central dense band. The other two cells are characterized by smaller, lessdense granules and presumably function in releasing the animal from substrates. The ducts of both gland types extend to the tail tip where they terminate in a common crescent-shaped space. Their secretions are released to the outside through two pores on the left side of the tail tip. There is no spinneret valve in this nematode. The muscles of the tail and of the mid-body region are developed to the same extent.The caudal gland apparatus can be compared with the duo-gland adhesive organs of other interstitial animals, but its homology with either these organs or the caudal glands of other nematodes is uncertain. Theristus caudasaliens is described as a new species.
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    Bifurcate sensilla on the tarsi of female black flies, Simulium venustum (Diptera: Simuliidae): Contact chemosensilla adapted for olfaction? (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 165 (1980), S. 1-11 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The ventral surface of the most proximal tarsomere of each mesothoracic leg of the female black fly, Simulium venustum Say, bears approximately 60 bifurcate sensilla. Externally, a sensillum appears as a hair set into an asymmetric socket and with the distal tip flattened into two flared lobes. A single pore opens into a short groove at the base of the lobes. The hair shaft is divided into two lumina, one of which contains the dendrites. Each sensillum is innervated by four neurons, the dendrites of which extend unbranched to the pore. Sensillum liquor bathes the dendritic tips and extends through the pore into the adjacent groove and across part of the lobes. A sieve-like structure exists in the pore region of many if not all sensilla. At least two sheath cells are associated with each sensillum.It is suggested that, although the bifurcate sensilla have the internal structure associated with known contact chemosensilla, they have secondarily acquired an olfactory function which is facilitated by the flattened lobes which increase the adsorptive surface area.Along each side of the bifurcate sensilla is a row of sturdy spines, each innervated by a neuron with a tubular body, a characteristic of cuticular mechanoreceptors. These spines are likely tactile sensilla.
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    Structure of the dermal scales in gymnophiona (Amphibia) (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 165 (1980), S. 41-54 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Histology and cytology of dermal scales of the gymnophionans Ichthyophis kohtaoensis and Hypogeophis rostratus reveal their structure and the nature of their mineralization.Dermal scales are small flat disks set in pockets in the transverse ridges of the skin. Each pocket contains several scales of various sizes. A ring of “hypomineralization” of varying diameter may occur on scales of a particular dermal pocket but bears no relation to the diameter of these scales.Three different layers form the scales and are seen on sections perpendicular to the surface. The cells of the basal layer lie deepest. Each of the two or three more superficial fibrous layers is composed of bundles of fibres that are oriented in parallel. The orientation varies among layers. The striation of the fiber scales has a periodicity comparable to that of the surrounding dermal fibers. Squamulae form a discontinuous layer on the scale surface and are the only mineralized part of the scale. The minerals are deposited both on the collagen fibers passing from the fibrous layers into the squamulae, and in the interfibrillar spaces. Spherical concretions, either isolated or coalescent, reaching up to 1 μm, are found on the surface of the squamulae.The dermal scales of Gymnophiona present some analogies with those of evolved bony fishes. Their characteristics could make them an original model for the study of mineralization.
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    Light and electron microscopic studies of crayfish hemocytes (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 165 (1980), S. 67-83 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Using light and electron microscopy, three hemocyte types are described in the hemolymph of the crayfish. The coagulocyte comprises 65% of the total hemocyte number and contains medium-sized cytoplasmic granules, abundant dilated rough endoplasmic reticulum, and a highly developed Golgi complex. It rapidly undergoes cytolysis in vitro and participates in coagulation by releasing the contents of its granules to the hemolymph. The granulocyte comprises 31% of the total hemocyte number and is capable of phagocytosis. It contains large, irregularly shaped cytoplasmic granules, a moderately developed Golgi complex, and moderate amounts of non-dilated rough endoplasmic reticulum. During coagulation in vitro, the cell attaches and spreads onto the substratum; this is followed by a slow intracellular granule breakdown and cytolysis. The amebocyte comprises 4% of the total hemocyte number and it is also capable of phagocytosis. It possesses small cytoplasmic granules, many vacuoles, a moderately developed Golgi complex, and large amounts of smooth endoplasmic reticulum. It is distinguished from the other two cell types by being stable and motile in vitro.
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    Intrinsic organization of snake lateral cortex (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 165 (1980), S. 85-116 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Lateral cortex is the most laterally placed of the four cortical areas in snakes. Earlier studies suggest that it is composed of several subdivisions but provide no information on their organization. This paper first investigates the structure of lateral cortex in boa constrictors (Constrictor constrictor), garter snakes (Thamnophis sirtalis), and banded water snakes (Natrix sipedon) using Nissl and Golgi preparations; and secondly examines the relation of main olfactory bulb projections to the subdivisions of lateral cortex using Fink-Heimer and electron microscopic preparations.Lateral cortex is divided on cytoarchitectonic grounds into two major parts called rostral and caudal lateral cortex. Each part is further divided into dorsal and ventral subdivisions so that lateral cortex has a total of four subdivisions: dorsal rostral lateral cortex (drL), ventral rostral lateral cortex (vrL), dorsal caudal lateral cortex (dcL) and ventral caudal lateral cortex (vcL). Systematic analyses of Golgi preparations indicate that the rostral and caudal parts each contain distinct populations of neurons. Rostral lateral cortex contains bowl cells whose dendrites arborize widely in the outer cortical layer (layer 1). The axons of some bowl cells can be traced medially into dorsal cortex, dorsomedial cortex and medial cortex. Caudal lateral cortex contains pyramidal cells whose somata occur in layers 2 and 3 and whose dendrites extend radially up to the pial surface. In addition, three populations of neurons occur in both rostral and caudal lateral cortex. Stellate cells occur in all three layers and have dendrites which arborize in all directions. Double pyramidal cells occur primarily in layer 2 and have dendrites which form two conical fields whose long axes are oriented radially. Horizontal cells occur in layer 3 and have dendrites oriented concentric with the ependyma. Fink-Heimer preparations of snakes which underwent lesions of the main olfactory bulb show that the primary olfactory projections to cortex are bilateral and restricted precisely to rostral lateral cortex. Electron microscopic degeneration experiments indicate that the olfactory bulb fibers end as terminals which have clear, spherical vesicles and asymmetric active zones. The majority are presynaptic to dendritic spines in outer layer 1.These studies establish that lateral cortex in snakes is heterogeneous and contains two major parts, each containing two subdivisions. The rostral and caudal parts have characteristic neuronal populations. Primary olfactory input is restricted to rostral lateral cortex and seems to terminate heavily on the distal dendrites of bowl cells. Axons of some of these cells leave lateral cortex, so that the rostral lateral cortex forms a direct route by which olfactory information reaches other cortical areas. The functional role of caudal lateral cortex is not clear.
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    The caudal neurosecretory system of Poecilia sphenops (Poeciliidae) (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 165 (1980), S. 157-165 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The caudal neurosecretory system of the molly, Poecilia sphenops (Poeciliidae) was studied by light and electron microscopy. In this species the cell bodies form a focal nuclear group in the caudal spinal cord. The neurosecretory cells are in contact with glial elements, axon terminals, and the lumen of the central canal. The axons of the neurosecretory cells form a definitive tract, which leaves the spinal cord proper to penetrate a well defined neurohemal organ, the urophysis. The urophysis contains an abundance of neurosecretory granules within the neurosecretory axonal processes. This study is the first ultrastructural study of the caudal neurosecretory system in this family of fishes, which has been used as a neuroendocrine model. This species acclimates easily to the laboratory aquarium and may be most suitable for further studies on the effects of changes in external salinity on the caudal neurosecretory system.
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    Scaling of subunit structures in book lungs of spiders (Araneae) (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 165 (1980), S. 167-174 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The relationships between dimensions of book lung subunits were measured and analyzed as a function of body size in diverse spiders over a body mass range of 3.4 to 3,190 mg. Book lungs are the characteristic respiratory gas exchange organs in these arachnids. Actual gas exchange occurs across numerous air-filled cuticular plates, which invaginate hemolymph sinuses within the abdomens of these animals. Characteristic linear dimensions of these air-filled compartments reflecting diffusion paths scaled to the 0.2 power of body mass and showed only a fourfold increase over the size range in the sample. This deviation from isometric scaling in the direction obtained and its numerical similarity to scaling of alveolar dimensions to body size in vertebrates was interpreted as an adaptation to reduce diffusion distances between these compartments and vascular fluids. Conversely, lengths and widths of these plates scaled to the one-third power of body mass, isometric scaling, and increased between six-and eightfold over the size range. This result is consistent with the hypothesis that respiratory gas distribution within spider lungs is achieved by convective mixing as has been recently hypothesized.
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    Erratum (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 165 (1980), S. 223-223 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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    URL: http://dx.doi.org/10.1002/jmor.1051650209
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    Fine structure of the midgut posterior caeca in the crustacean Orchestia in intermolt: Recognition of two distinct segments (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 165 (1980), S. 261-284 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This study carried out on the posterior caeca of Orchestia in intermolt by means of light and electron microscopy shows that the diverticula of the midgut consist of two segments which are different from an anatomical point of view. The distal segment is in close relationship to the dorsal blood vessel, whereas the proximal segment, twice as long as the distal one, only touches the haemocoel. The cells of the distal segment are characterized by a brush border, some apical extrusions, a great number of ribosomes, rough endoplasmic reticulum, often associated with the mitochondria, the matrix of which is clear, high activity of the Golgi complexes, and a great development of extracellular channels. All these features indicate an activity in synthesizing proteins and transport. In the proximal segment, the cells are characterized by a striated border, reduced intercellular space, and especially by a great development of the smooth endoplasmic reticulum sometimes associated with mitochondria having a dense matrix. These diverse features indicate absorption ion and water transport. From an ultrastructural point of view, the posterior caeca of Orchestia cannot be considered homologous to the Malpighian tubules. Whereas during molting the posterior caeca of Orchestia are sites of calcium storage, during intermolt they are probably involved in the processes of water and mineral regulation and excretion.
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    Spermathecal ultrastructure of the insect Rhodnius prolixus stal (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 166 (1980), S. 1-25 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The paired spermathecae of Rhodnius are simple tubular out-pocketings of the common oviduct. Each consists of a short muscular proximal duct and the distal glandular region with a blind tapering end. The spermathecal wall has a cuticular intima, slender columnar epithelial cells and ensheathing longitudinal striated muscle, connective tissue, tracheoles, and nerves. Glandular epithelial cells possess an elaborate apical secretion-filled tubular inpocketing with an extensively folded plasma membrane. Laterally, cells interact by desmosomes, septate desmosomes, and extensive interdigitations. The cytoplasm is rich in longitudinally oriented microtubules associating with membrane densities along the invagination, lateral, and basal plasmalemmae. Apical concentration of mitochondria suggests their role in secretion or ion transport. The possible role of the spermathecae in maintaining the stored luminal sperm and its role in transmitting the mating stimulus is considered in light of the epithelial ultrastructure. The ultrastructure of the spermathecae of Rhodnius differs significantly from that of other insects.
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    Innervation of the parathyroid in the european starling (Sturnus vulgaris) (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 166 (1980), S. 65-80 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Anatomical studies were conducted to characterize the source, type, and distribution of parathyroid gland innervation in European starlings. Denervation experiments demonstrated that the parathyroid glands and adjacent carotid bodies are innervated by nerve fibers originating in the nodose ganglion of the vagus nerve. In the parathyroid parenchyma, these fibers terminate adjacent to chief cells or near vascular smooth muscle. Vagal fibers also form synapses with catecholamine-containing glomus cells of the carotid body. Blood that first perfuses the carotid body subsequently perfuses the parathyroid parenchyma. These observations suggest that vagal innervation may influence parathyroid function in starlings either through direct chief cell innervation or through alteration of vascular perfusion. A neurohemal relationship also may exist between the carotid body and parathyroids.
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    Functional morphology of the masticatory musculature of the rodent subfamily microtinae (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 165 (1980), S. 205-222 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Voles and lemmings are the most successful group of graminivorous rodents, but the adaptations allowing them to enter this niche are not fully known. Dissections of the masticatory musculature of the 12 genera and subgenera of North American microtines show an increase in the potential anterior vector component and in the potential vertical vector component of these muscles relative to the molar tooth row. The result is a separation of the compressive and propulsive functions of the masticatory muscles during the power stroke of mastication. This has led to the formulation of a propalinal “swing” hypothesis which is supported by vector analyses of the musculature.
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    Masthead (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 165 (1980) 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    URL: http://dx.doi.org/10.1002/jmor.1051650301
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    Cytodiffrentiation in the accessory glands of Tenebrio molitor. VI. A congruent map of cells and their secretions in the layered elastic product of the male bean-shaped gland (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 166 (1980), S. 289-322 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The morphology of the bean-shaped accessory glands (BAGs) of males of Tenebrio molitor is described. All cells in the secretory epithelium are long and narrow (300-400 mμ × 5 mμ). The seven types of secretory cells are distinguished from one another by the morphology of their secretory granules. Granule substructure varies from simple spheres with homogeneous electrondense contents to complex forms with thickened exterior walls or with crystalline and membranous contents. Individual cell types were mapped by staining whole glands with Oil Red O, and the cell distributions were confirmed by wax histology and ultramicroscopy. The secretions of all seven cell types form a secretory plug composed of seven layers. During mating, the secretory plug from each BAG is forced into the ejaculatory duct by contractions of a sheath of circular muscle. The mirror image plugs from symmetrical BAGs fuse and are transformed into the wall of the spermatophore.
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    Announcement and call for papers. International conference on factors and mechanisms influencing bone growth (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 166 (1980), S. 387-387 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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    URL: http://dx.doi.org/10.1002/jmor.1051660307
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    Chromosome studies. II. Synapsis in the Tettigidae, with special reference to the presynapsis splitContribution no. 121 from the Department of Zoölogy, Kansas Agricultural Experiment Station, Manhattan. (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 51 (1931), S. 119-145 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Notes: Homologous chromosomes entering parasynapsis are already split. This split evidently originates in each chromosome in the resting period prior to the last spermatogonial division. In the prophase of this division the daughter chromonemata in each halfchromosome were probably incompletely separated, but the succeeding telophase effects the completion of their separation. These processes are accompanied and suceeded by an elongation, straightening, and general paralleling of the split threads and by an elongation of the cell and its nuclear space.Parasynapsis begins with intimate approximation of the daughter threads in each homologue and is continued by approximation of the homologues at the usual [bouquet] and [zygotene] periods. There results the [diplotene] thread, which therefore consists of four completely distinct strands, but which exhibits a [two-strand] appearance due to parasynapsis between daughter chromonemata being further advanced than that between homologues.The pairing process begins at the distal ends and proceeds proximally. With parasynapsis complete, the nucleus enters the [diffuse] stage On emergence, disjunction is seen to have progressed from the distal ends to near the proximal ends in each pair and the [tetrads] have taken form. In the prephase that follows each strand in a tetrad may [crimp] independently, and with the condensation and matrix (?) formation that accompany it there results the spermatocyte ‘tetrad.’
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    Masthead (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 51 (1931) 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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    URL: http://dx.doi.org/10.1002/jmor.1050510201
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    The evolutional significance of the chromosomes of Aphididae (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 51 (1931), S. 373-433 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: An investigation into the number of chromosomes in thirty-seven species of Aphidiae belonging to twenty-seven geaera has shown that there is but one sex chromosome in the male cells of all but one species of Aphididae. That exceptional species is Euceraphis betulae Koch.The number of chromosomes and body characters are so closely correlated that we can safely judge the evolutional scale of any aphid by its number of chromosomes.In Aphididae the least number of chromosomes seems to be the most primitive.The number of chromosomes varies with the genera. The highest number is 1811 + X = 37 chromosomes, the lowest being 211 + X = 5 (diploid in male).The increase in the number of chromosomes seems to have been brought about by transverse divisions of the primitive chromosomes.The genus Tuberolachnus with 311 + X = 4 elements (♂) represents altogether different chromosomes characters from the genus Pterochlorus with 8 elements.In the genera Periphyllus and Calaphis there are species with a small m-element which is bivalent.
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    The effects of vitamin-E deficiency on the development of the chickContribution no. 406 from the Zoölogical Laboratory, University of Illinois. (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 52 (1931), S. 47-89 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In an investigation of the hatchability of eggs from hens fed on a diet deficient in vitamin E Card found that all embryos from these eggs died during development. Study of these chicks showed that a variety of conditions were responsible for death:During early development the rate of growth and differentiation was definitely slower than under normal conditions, but malformations were rare. Some embryos died during the first two days, due to disintegration of the circulatory system or its failure to become established. At the end of the fourth day there was a definite critical period which few specimens survived and by this time distinet pathological conditions had arisen in extra-embryonic structures. These involved wiping out of the vitelline circulation by establishment of a lethal ring in the blastoderm. This structure was produced by intensive cell proliferation in the mesoderm which resulted in choking out vitelline blood vessels and their subsequent degeneration. It also caused obliteration of the exocoele, with consequent failure of the allantois to expand. In addition, many embryos showed profuse haemorrage into the exocoele. The source of bleeding was most frequently in the atrium of the heart, and at the actual rupture peculiar cells occurred which were probably histiocytic mesenchyme cells.Although death was due directly to causes enumerated above, the ultimate responsibility rests upon conditions set up by them, namely: starvation, asphyxiation, and loss of the medium (blood) by which to carry on metabolic exchange.
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    Recovery from immersion in water. An index of metabolism and the condition of the gonads in Drosophila melanogaster Meigen and Popillia japonica Newm. (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 51 (1931), S. 435-465 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In some insects the selection of individuals which recover in equal periods of time from immersion in water may be used to obtain material of approximately uniform physiological state; Drosophila melanogaster, Meigen, was found to have a mean of recovery for the males 0.97 ± 0.542 minute later than the females, which would indicate a lower metabolic rate for the males. The Japanese beetle, Popillia japonica Newm., was found to have a mean of recovery from immersion in water of both sexes the same in August, while in September the males were retarded by 8.1 as compared with females. This would indicate that the males have and equal me abolic rate in August with the females and a lower rate in September. Carbon dioxide, hydrogen, and nitrogen produce in the flies a condition of asphyxiation similar to immersion in water. [Vestigial] flies recover from immersion in water in a fashion similar to ‘wild’ flies.The recovery periods from immersion in water in the flies can be used to group individuals into those possessing approximately equal egg-laying capacities and to isolate spent individuals from others still capable of laying eggs. Yeast appears to be more of a stimulant to egg laying than it is to larval growth. Groups of flies which were fed yeast were found to average 71 per cent increase in egg laying over groups of flies that were not fed yeast. The O2 consumption of the groups of flies actively laying eggs, as contrasted with the groups which were not so active, was found in the former to be 32.9 per cent greater.
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    Masthead (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 52 (1931) 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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    URL: http://dx.doi.org/10.1002/jmor.1050520101
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    A study of living sperm cells of certain grasshoppers by means of the ultraviolet microscope (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 52 (1931), S. 91-113 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This paper discusses very briefly the ultraviolet microscope and the developments which have led to a successful technique for optically sectioning living cells; also the ultraviolet photomicrographs of living sperm cells of certain grasshoppers, which show clearly the spinning out of the chromonema from solid blocks of the diatene stage, the pairing of same in the leptotene stage, the development of the tetrads, the final distribution of the chromosomes in the resulting spermatids and their return to a spiral chromonema, each inclosed in its own vesicle. The details of the cytoplasm are equally well brought out.
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    Thermal relationships in the neutral-red reaction (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 52 (1931), S. 165-194 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Neutral-red staining in Daphnia, legume seeds, starfish eggs, and Palaemonetes shows reactions to temperature changes which may be correlated with the thermal reactions of enzymes.
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    Masthead (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 52 (1931) 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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    URL: http://dx.doi.org/10.1002/jmor.1050520201
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    Vertebrate cephalogenesis. VI. A. The velum - its in head building - the hyoid. The Velata. The origin of the vertebrate head skeleton. B. Myxinoid characters inherited by the teleostomi (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 52 (1931), S. 309-371 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The oldest parts of the fibrous, cartilaginous, and bony head skeleton of vertebrates descend from the amphioxid ancestors of the myxinoid fishes. The skeleton of the velum and jaw bars of the amphioxids transform into the jaw apparatus and hyoid-velar head skeleton of the myxinoids, and some parts are passed on by inheritance to the teleostome fishes (sturgeons). These anatomical characters prove descent with modification. The theory of the origin of jaws and hyoid from branchial cartilages is not supported by the facts, as both jaws and hyoid structures were developed long before branchial cartilages furnished material for head building. The Velata, the oldest of living vertebrates, include the amphioxids and marsipobranchs, and are marked off from the higher forms by the important organ, the velum, which separates the prebranchial from the branchial head. A remnant of the velum inherited by all of the higher vertebrates is the hyoid mechanism - an important anatomical landmark.
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    The ontogenetic history of the mitochondria of the hepatic cell of the white rat (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 52 (1931), S. 485-511 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This work was designed to determine the ontogenetic variability of the morphology of mitochondria of the hepatic cell.The mitochondria of the cells of the hepatic diverticulum are minute spheres. These spheres enlarge, become associated, forming beaded filaments, which in turn become smooth filaments, the process culminating in the twenty-day fetus. There is no individual or lobular variabillty in fetuses of a given length. One-half day before birth the above process is reversed, so that separate spheres are found in the eight- to twelve-hour young. This enlargement and enspherulation are accompanied by an accumulation of large quantities of glycogen. After this age, the spheres become associated into beaded filaments again and the glycogen disappears, the cycle ending at thirty-three hours. From two to eight days of age there is great individual variability.Mitochondrial morphology characterstic of the adult is first found in the fourteen-day young, when cells contain long, smooth or beaded filaments, rods, and spheres. There is no lobular variation as to types of mitochondria, but only in numbers, the cells around the central vein containing fewer mitochondria than other cells of the lobule. Variation between individuals after birth is due to something other than age, type of food, period of digestion, and length of starvation. Fat is formed within spherical chondriosomes.
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    Chromosomes of three species of mantidae (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 52 (1931), S. 525-533 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: There are twenty-seven spermatogonial chromosomes in Tenoder'a sinensis, three of which are larger than the others and lag behind in anaphase. These three chromosomes have been traced through the prophases of the first spermatocyte to the metaphase, where they appear as a hexad. In the first spermatocyte division two of the constituent diads of the hexad pass to one pole, the remaining one to the other, thus giving rise to two types of second spermatocytes, one with thirteen and the other with fourteen chromosomes. There are twenty-eight chromosomes in somatic metaphases of the female; four of these chromosomes are larger than the others. The sex chromosomes of the male are represented by the formula Xa + Y + Xb, that of the female by 2Xa + 2Xb.Similar conditions are reported for Mantis religiosa and Stagmomantis carolina.
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    Insect development. II. Mitotic activity in the grasshopper embryo (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 51 (1931), S. 613-618 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The onset of hibernation in Melanoplus differentialis eggs kept at high temperatures is accompanied by a fairly abrupt cessation of cell division. The total number of mitotic figures present in the different individuals of a series of embryos of this grasshopper, from eggs kept for eighteen to twenty days at 25°C. from the time of saying, was found to vary between 1000 and 4400. In contrast to the conditions found in eggs of this age, embryos from eggs kept twenty-seven days at 25°C., as well as those older and still in the hibernating state, contained few or no dividing cells. During the course of the work it was found that, in rare cases, hibernation failed to occur, a few or many of the eggs developed without a pause when kept at 25°C., and hatched at approximately the thirty-eighth day. The detection of variations in the rate of mitotic activity over short periods, as originally planned, was found impossible, because of the comparatively small number of embryos used.
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    Some histological effects of ultrasonic waves on cells and tissues of the fish lebistes reticulatus and on the larva of rana sylvatica (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 52 (1931), S. 155-164 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Some pathological effects of supersonic waves produced by the piezo-electric oscillator described by Wood and Loomis ('27) are described.Death of fish and frogs was due to haemolysis of erythrocytes within the gill capillaries. Disruption of gill filaments, trauma, and extravasation in the head and gill region and in the peripheral musculature were noted.No effect on the nervous system was apparent histologically.Organisms were not killed in water under hyper- or hyponormal pressures. In these cases no cavitation of gases took place.Isolated frog sartorius muscle in Ringer's was not damaged.Bubbles of gas were easily observed within the muscle cells of the tadpoles when such cells were not more violently disturbed. Such bubbles were abundant in the more fluid muscles of four- or five-day tadpoles, less abundant in 15- to 35-mm. Lebistes, and entirely lacking in adult frog sartorius. Protoplasmic viscosity differences probably explain the gradient.The above-observed intracellular cavitation explains the muscular destruction, the haemolysis, the change in specific gravity of organisms subjected to the wave treatment, and may offer light upon the stimulatory effect of such waves on excitable tissues (compare Harvey, '28).
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    The anatomy of diplodinium medium (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 52 (1931), S. 195-215 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In this paper evidence is given in support of the author's statements (Rees, '30) that in ciliates in the genus Diplodinium a neuromotor apparatus, as described and figured by Sharp ('14), could not be differentiated. For the study of minute anatomy ciliates were cut into serial sections 3 μ thick. The body which in D. medium appeared to correspond to the motorium of D. ecaudatum was shown to be a fold of the middle layer of ectoplasm. Fibers, described and figured by Sharp as connecting the motorium to the organelles of locomotion and of food taking and to a ring about the esophagus, could not be differentiated. Other fibers which Sharp designated as opercular were shown to be part of a fibrillar complex extending throughout the middle layer and the inner boundary layer of ectoplasm. The walls of the esophagus were shown to be formed by the fused middle and inner layers of the ectoplasm. The esophageal fibers therefore belong also to the above-mentioned fibrillar complex. In D. medium a system of esophageal membranelles was differentiated, described, and figured. The ciliary systems of Paramaecium ecaudatum and of Diplodinium medium were shown to be strikingly similar. The principle of descent from a common ancestor adequately explains the above similarity, but is out of harmony with the discrepancies between Sharp's account of D. ecaudatum and this account of D. medium.
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    A detailed study of the endoderm of hydra (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 52 (1931), S. 249-275 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The flagella of the endodermal cells of hydra have their origin in the form of a cytoplasmic spherule which appears on the cell membrane just above the blepharoplast. This spherule moves outward, and in doing so forms a small cylinder, which, in time, flattens down into a ribbon-like flagellum, the edge of which is slightly thickened. Endodermal cells were found to bear from one to five of these flagella. Dissociated endodermal cells become amoeboid and are able to move about quite freely, taking up particles of food with pseudopods; these cells are also able to elaborate flagella. In the normal well-fed hydra the endodermal cells are found to fragment endogenously; these endogenous fragments pass to the tentacles and other outlying regions, where they are taken up by the endo-epithelio cells lining these regions. The endoderm is frequently thrown into villi of quite large size: these villi, when studied over a period of days, are found to deteriorate; the cells which composed them wander to the tentacles, buds, and basal regions by means of their flagella and amoeboid movement, where they deteriorate, the cell particles being taken up by the epithelio cells lining these areas.
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    A demonstration of the vacuome and the golgi apparatus as independent cytoplasmic components in the fresh eggs of teleostean fishes (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 52 (1931), S. 277-307 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The most important conclusion of this investigation is that the vacuome and the classical Golgi apparatus are independent cell components in the oocytes of Ophiocephalus and Rita. The same conclusion has been arrived at by Nath in Rana tigrina. The vacuoles, the Golgi elements, and the mitochondria can be seen intra vitam side by side.In Ophiocephalus the vacuoles give rise to albuminous yolk, as has been rightly claimed by Hibbard for Discoglossus and by Hibbard and Parat for Perca and Pygosteus. The Golgi elements give rise to the fatty yolk as in so many other forms of oogenesis described by Nath and others.In Rita the fate of the vacuoles and the Golgi elements is unknown, as the fish suddenly disappeared from the Ravi during the spawning period.
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    Spermatogenesis in sturnus vulgaris: Refractory period and acceleration in relation to wave length and rate of increase of light rationStudies on the sexual cycle in birds, no. VII. Aided by a grant from the Committee for Research in Problems of Sex of the National Research Council, 1930-1931. (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 52 (1931), S. 403-427 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Between December 10th and January 24th, using red, green, and white electric lights at equal intensities of about 1.7 foot-candles, sixty-nine males, with females, were subjected nightly to, (a) constant six- and six-and-one-quarter-hour periods of illumination; (b) periods increasing gradually from one-quarter to six and one-quarter hours; (c) no added light (controls), in a basement room lighted by day from three large windows. Relative heat intensities reaching the birds were: for white, 1; for green, 2.5; for red, 10.Birds were killed for testis study at 5, 12, 16, 22, and 23 days.Refractory period was shorter, and modification of spermatogenic activity much greater, under a than under b types of treatment, as compared with controls. Effects were also more consistent.Descending order of testis activity induced at all stages was red, white, control, green, under both a and b.Effects on testis activity are not proportional to heat intensity of incident light, but depend on wave length, since green effect is not intermediate between those of white and red, as its heat intensity is. Green inhibited germ-cell activity even in birds already at normal midwinter minimal condition.Constant six-hour red-light treatments, of this intensity, induced flrst appearance of metamorphosing sperms in twenty-three days in midwinter.Apparatus and mode of light regulation and measurement are described.
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    Modified mitosis in the chick embryo (1931)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 52 (1931), S. 535-563 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A study of cell division in the chick embryo has revealed in striated muscle and in the early stages of all the principal tissues and organs a process, followed by the greater percentage of the dividing nuclei, which resembles amitosis, but is undoubtedly a highly modified form of mitosis. This process is designated ‘modified mitosis’. The belief that this is essentially mitotic rests upon the fact that a number of discrete bodies may be distinguished in the one or two chromatin masses of each nucleus. These masses, or ‘mulberries’, might easily be mistaken for nucleoli or karyosomes were it not that they exhibit division by elongation and constriction. These structures probably represent masses of minute and closely clumped chromosomes in somatic number dividing in a qualitative and a quantitative fashion. As additional evidence there are present between the dividing mulberries exceedingly fine fibers which possibly represent an attempt at spindle fibers. Neither centrosomes nor asters are present, but since, if present, they would have to be of the intranuclear variety (the nuclear membrane never disintegrating) their absence is immaterial. The nucleus divides not by constriction, but by the formation of a nuclear plate. This process of modified mitosis is probably a device which favors the speed of nuclear proliferation necessary to such rapidly growing tissues.
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    Masthead (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 163 (1980) 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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    URL: http://dx.doi.org/10.1002/jmor.1051630101
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    Structural modulation of the surface and cytoplasm of oocytes during vitellogenesis in the lobster, Homarus americanus. An electron microscope-protein tracer study (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 163 (1980), S. 13-26 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The present investigation describes the ultrastructural changes which occur at the surface and in the cytoplasm of developing oocytes of the lobster, Homarus americanus, during vitellogenesis. The immature oocytes showed no surface specializations of the oolemma and no pinocytotic activity was observed. Horseradish peroxidase (HRP) tracer studies showed penetration of the tracer into the perivitelline space, but no uptake by the oocytes. The surfaces of oocytes examined during vitellogenesis, when yolk protein accumulation was maximal, exhibited numerous microvilli that projected into the perivitelline space, often appearing to be embedded in the follicular cell mass. In addition, the plasma membrane of vitellogenic oocytes contained many pinocytotic pits frequently situated at the bases of microvilli. The perivitelline space was engorged with electrondense material which appeared similar to that contained in pinocytotic structures of the oocytes. Vitellogenic oocytes incubated in HRP showed uptake of tracer reaction product by the coated pits and vesicles of the oolemma. Aggregation and subsequent fusion of these vesicles into large multivesicular bodies of ingested material were also observed in vitellogenic oocytes. Animals artificially induced to undergo vitellogenesis exhibited modulations of oocyte ultrastructure similar to those of normal vitellogenesis, notably, pinocytotic incorporation of extra-oocytic material and hypertrophy of oocyte surface microvilli. This study supports the hypothesis for a dual source of yolk protein in the American lobster.
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    Annular bands of lymphoid tissue in the intestine of the mallard duck Anas platyrhynchos (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 163 (1980), S. 1-8 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The annular bands were studied by light and scanning electron microscopy in normal and hormonally bursectomized ducks (Anas platyrhynchos). The four annular bands are normal lymphoid structures of 5-10 mm wide and encircle the intestine at regularly spaced position, two on each side of Meckel's diverticulum. The anterior three are well defined, complete rings whereas the posterior-most encompasses about one half of the gut circumference. The bands are characterized by prominent follicles in the tunica muscularis, submucosa, and lamina propria. In addition, large numbers of diffusely organized lymphocytes fill the lamina propria and villus cores. Each nodule possesses germinal centre activity, as revealed by the characteristic macrophage content seen in 1.0 μm sections.The bands were present in rudimentary form at hatching. Lymphoid nodules began to develop at day 3 and were morphologically mature at day 98 posthatching. When viewed in the scanning electron microscope, the mucosa of the lymphoid areas was seen to be arranged in tortuous folds, often with irregular fusions. Following hormonal bursectomy, the bands were present, although difficult to detect, and lacked distinct nodules and germinal centres. The mucosal surface still appeared irregularly folded in the SEM, but the folds were more slender with convoluted surfaces.
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    An ultrastructural study of the craniocaudal continuation of the glycogen body (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 163 (1980), S. 45-58 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: An ultrastructural analysis of the chicken glycogen body and its craniocaudal continuation areas shows a continuum of astroglial cell types. Characteristic glycogen body astroglia are confined to the classically defined body located in the chicken lumbosacral spinal cord. These are large cells which have an eccentric dark nucleus surrounded by a rim of dense cytoplasm which contains the usual complement of organelles. The remainder of the cell volume is occupied by alpha and beta glycogen particles interspersed with a flocculo-granular material continuous with the main cytoplasmic mass. Astroglial cells of continuation areas usually have a light cytoplasm and a centrally placed nucleus. They contain beta glycogen particles of varying sizes, but like the glycogen body cells, may have beta particles as large as 45 nm. Such particles, which resemble four leaf clovers in shape, are suggestive of an ordered substructure. Gliofilaments are not always conspicuous in astroglial perikarya, but large numbers of them are present in the processes. Although the continuation areas are mostly confined to gray matter regions, the contained astroglial processes exhibit circular, triangular, or cylindrical shapes and form an unpatterned mosaic. Astrocytic processes forming the glia limitans on the anterior and posterior margins of the cord often contain conspicuous amounts of glycogen. The ultrastructural identification of such large amounts of glycogen within the chicken nervous system suggests that it plays a major role in avian neural metabolism.
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    Colic modifications in iguanine lizards (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 163 (1980), S. 79-93 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: All lizard species of the subfamily Iguaninae except Amblyrynchus cristatus possess from one to eleven transverse valves in the proximal colon. Valves are of two kinds: circular (sometimes with a sphincter valve) or semilunar. Circular valves (if present) always occur proximally to semilunar valves. Intraspecific variation in the number and type of valves is small, but increase with modal number of valves. No significant ontogenetic change in number of valves could be demonstrated. Colic valves in iguanine lizards apparently evolved as simple infoldings of the medical colic wall.Comparisons are made with colic modifications occurring in other lizard families. Herbivorous species of the Scincidae, Agamidae, and Iguanidae are the only lizards known to exhibit colic partitioning, suggesting that the evolution of these structures is intimately related to the evolution of herbivory in these lizards. The potential taxonomic and phylogenetic importance of lizard colon anatomy is discussed.
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    Ultrastructure of the y-organs of Cancer antennarius in normal and de-eyestalked crabs (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 163 (1980), S. 167-174 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The paired Y-organs of crustaceans control the molting process. In males of C. antennarius, these glands are opalescent, lobulated, epithelioid structures embedded in brown fatty tissue. Cells in the periphery extend processes to the connective tissue capsule, an arrangement that suggests increased surface area for metabolic exchange. The processes contain mitochondria and are tipped distally with electron dense material. The cytoplasm, scarce relative to nuclear volume, contains vesicles, polymorphic mitochondria with tubular cristae, and numerous free ribosomes, but little in way of smooth or rough endoplasmic reticulum or Golgi complexes. Progressing from intermolt to the premolt stage, mitochondria, as well as vesicles, and electron-dense particles in peripheral processes increase somewhat in number. Also, heterochromatin masses concentrate adjacent to the nuclear envelope. Eyestalk removal, which induces premolt stages in some species, did not produce consistent change in Y-organ substructure in C. antennarius. Although evidence is accumulating that Y-organs secrete a steroid molting hormone during late intermolt-premolt, the substructure of the glands exhibits neither (a) striking changes with the molt cycle, nor (b) all the characteristics typical of vertebrate steroid hormone synthesizing glands. Nevertheless, the structural features, respectively, are consistent with biochemical evidence that Y-organs (a) rapidly take up and convert sterol precursor and secrete a product without its accumulation or change in total sterol pool size, and (b) apparently cannot synthesize the sterol precursor. Y-organ cytology closely resembles that of some vertebrate steroid hormone secreting glands in which this synthetic capacity is minimal.
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    Regeneration of colonic mucosa in the rat (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 163 (1980), S. 203-215 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: As part of a study of ulcer formation and healing, regeneration of colonic mucosa in rats was studied following placement of a surgical lesion. Alterations in mucosubstances and connective tissue were examined and their possible significance discussed.The sequence of events in healing was: (1) The mucosa adjacent to the lesion tipped into the lesioned area. The crypts in this mucosa became lined with cells which contained no mucus and had no striated borders. Later in the experimental period, these undifferentiated cells gave rise to cells containing carboxymucins. Cells containing sulfomucin, neutral mucin, or having striated borders arose from the carboxymucin cells. (2) An epithelial ledge of undifferentiated cells migrated onto a sulfated glycosaminoglycan, fibrous interface between necrotic and living tissue in the lesion. (3) Crypt formation began with the appearance of intraepithelial anlagen. (4) Crypts lengthened by a process of epithelial-connective tissue proliferation from the base of the crypt upwards. Following completion of connective tissue regeneration, crypts formed by invading the reestablished lamina propria. (5) The first mucous cells in the ledge contained carboxymucins. As crypt formation occurred, these cells gave rise to typical columnar absorptive cells, to cells containing sulfomucins, and to cells containing neutral mucins. (6) Lengthening of crypts ceased following the appearance of a sulfated acid glycosaminoglycan - collagenous layer deep in the submucosa.
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    Evolution of the feeding mechanism in primitive actionopterygian fishes: A functional anatomical analysis of Polypterus, Lepisosteus, and Amia (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 163 (1980), S. 283-317 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The comparative functional anatomy of feeding in Polypterus senegalus, Lepisosteus oculatus, and Amia calva, three primitive actinopterygian fishes, was studied by high-speed cinematography (200 frames per second) synchronized with electromyographic recordings of cranial muscle activity. Several characters of the feeding mechanism have been identified as primitive for actinopterygian fishes: (1) Mandibular depression is mediated by the sternohyoideus muscle via the hyoid apparatus and mandibulohyoid ligament. (2) The obliquus inferioris and sternohyoideus muscles exhibit synchronous activity at the onset of the expansive phase of jaw movement. (3) Activity in the adductor operculi occurs in a double burst pattern - an initial burst at the onset of the expansive phase, followed by a burst after the jaws have closed. (4) A median septum divides the sternohyoideus muscle into right and left halves which are asymmetrically active during chewing and manipulation of prey. (5) Peak hyoid depression occurs only after peak gape has been reached and the hyoid apparatus remains depressed after the jaws have closed. (6) The neurocranium is elevated by the epaxial muscles during the expansive phase. (7) The adductor mandibulae complex is divided into three major sections - an anterior (suborbital) division, a medial division, and a posterolateral division.In Polypterus, the initial strike lasts from 60 to 125 msec, and no temporal overlap in muscle activity occurs between muscles active at the onset of the expansive phase (sternohyoideus, obliquus superioris, epaxial muscles) and the jaw adductors of the compressive phase. In Lepisosteus, the strike is extremely rapid, often occuring in as little as 20 msec. All cranial muscles become active within 10 msec of each other, and there is extensive overlap in muscle activity periods.Two biomechanically independent mechanisms mediate mandibular depression in Amia, and this duality in mouth-opening couplings is a shared feature of the halecostome fishes. Mandibular depression by hyoid retraction, and intermandibular musculature, consisting of an intermandibularis posterior and interhyoideus, are hypothesized to be primitive for the Teleostomi.
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    An autoradiographic, biochemical, and morphological study of the harderian gland of the mouse (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 163 (1980), S. 349-365 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Biochemical and morphological properties of the Harderian gland of the mouse were examined by combining autoradiographic, biochemical, and electron microscopic techniques. Autoradiographs show that the radioactive carbon from [U-14C]glucose injected into the abdominal cavity is completely incorporated into the acid-insoluble substances within 30 minutes. The results of chemical analysis show that the main components of this gland are glyceryl ether diesters and phospholipids. Scanning electron microscopy shows numerous lipid droplets in the secretory cells and alveolar lumina. Myoepithelial cells lie between the secretory cell base and the basement membrane and have a basket-like distribution of processes as confirmed by hydrochloric acid and collagenase digestions. Myofilaments are demonstrated in the cytoplasm. Two types of secretory cells (A and B) comprise the alveolar epithelium and can be differentiated under the electron microscope. The cytoplasm of both contains numerous vacuoles. The vacuoles are almost empty in A cells, which are a more numerous constituent of the alveolar epithelium than B cells. However, the vacuoles of the B cells contain densely osmiophilic material. In both, cell types show a merocrine mode of secretion. Unmyelinated nerve cell endings occur in the interstices of the connective tissue, and contain clear or cored vesicles.
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    Quantitative studies on the skin of the paired species of lampreys, Lampetra fluviatilis (L.) and Lampetra planeri (BLOCH) (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 164 (1980), S. 39-46 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The number of mucous, club, and granular cells in the epidermis, and the number of rows of subcutaneous adipose cells, as well as the thickness of the epidermis and the dermal collagen layer, have been recorded for the larval and metamorphosing stages of the anadromous parasitic lamprey, Lampetra fluviatilis, and for the larval, metamorphosing, and adult stages of the nonparasitic lamprey, Lampetra planeri.In L. fluviatilis, the mucous cells predominated in all stages but were more abundant in fully metamorphosed individuals than in larvae. During metamorphosis, the number of granular cells increased continuously, whereas the club cells showed little change. Although lampreys do not feed during metamorphosis, there was an increase in the thickness of the epidermis and in the dermal collagen sheath; the latter increase probably foreshadows the increase in activity by the adults. Simultaneously, there is a reduction in the subcutaneous fat layer, which can be attributed to mobilization of lipid as an energy source.Changes similar to those just described for L. fluviatilis were also found in metamorphosing L. planeri. However, the pattern altered markedly during adult stages in this nonparasitic species. There were marked declines in the number of cells, in the thickness of the epidermis, in the width of the collagen sheath, and in the quantity of subcutaneous fat.
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    Masthead (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 164 (1980) 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051640201
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    Announcement (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 164 (1980), S. 213-214 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051640207
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    Ultrastructure of siliceous spicules and microsclerocytes in the marine sponge Neofibularia irata N. SP. (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 166 (1980), S. 51-63 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The marine sponge Neofibularia irata contains four different categories of siliceous spicules. These spicules are evident in the tissues as distinct bundles that act to increase the structural rigidity of the sponge. All spicules have a normal structural morphology with silica deposition around a hexagonal axial canal containing a crystalline axial filament. The megasclere strongyles are secreted in typical megasclerocytes. The sigma and raphid microscleres are secreted in individual microsclerocytes that are grouped together in parallel to form loose bundles. However, the microxea microscleres are apparently secreted in distinct tight bundles (trichodragmas) within a single cell. These cells, containing between 13 and 39 spicules, are grouped to form large packets of bundles of spicules.
    Additional Material: 21 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051660105
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    Spermatogenic columns, somatic cells, and the microenvironment of germinal cells in the testes of asteroids (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 166 (1980), S. 81-107 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Sixty-seven specimens of the common North Atlantic asteroid, Asterias vulgaris, were collected at seasonal intervals over a 2-year period and their testes observed with both light and electron microscopy. In the germinal epithelium, a predictable series of interactions between versatile somatic cells and germinal cells is repeated annually in relation to sequential events in spermatogenesis. For example, massive proliferation and differentiation of spermatogenic cells depend on the elaboration of thousands of spermatogenic columns, which are distinct cellular subdivisions of the germinal epithelium. Each fully developed column is composed of at least one somatic cell surrounded by ≍ 400 germinal cells. Such columns form only after intensive spermatogonial mitosis begins in the germinal epithelium. Single annual periods of spermatogenic proliferation and differentiation are initiated from 1 to 3 months out of phase in different individuals and overlap incompletely. Therefore, it is possible to observe testes that are entirely in the proliferative phase, entirely in the differentiative phase, or in both phases simultaneously. Detailed ultrastructural observations and preliminary autoradiographic data demonstrate that columns maintain their height for a variable period of time as germinal cells are generated near their bases, pass along their lengths, and differentiate near their tips; therefore, simultaneous proliferation and differentiation of more than one generation of germinal cells occur in the same column. Finally, formation of primary spermatocytes ceases basally, (terminating proliferation), and remaining columns degrade completely as germinal cells composing them differentiate or are phagocytized (terminating differentiation and spermatogenesis); resulting spermatozoa ultimately accumulate in the expandable lumen. It is proposed that spermatogenic columns provide the structural basis for organization of the microenvironment of small groups of spermatogenic cells (≍ 400 at a time) during proliferation and differentiation. Preliminary evidence from A. vulgaris and other species also suggests that somatic cells are temporally pluripotent and are variously involved in the formation, structure, and activities of columns, in extensive phagocytosis, and probably in contributing intrinsic (e.g., 1-methyl adenine and steroids) and mediating extrinsic (e.g., gamete shedding substance and nutrients) microenvironmental factors influential during spermatogenesis in asteroids. The prodigious spermatogenic capabilities of asteroids apparently depend on the generation of spermatogenic columns, on the progressive interaction of germinal and somatic cells before, during, and after columns form, and on the predictable effects of microenvironmental factors received and interpreted at the structural level of the spermatogenic column.
    Additional Material: 22 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051660107
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    Ultrastructural study of two kinds of muscle in sea anemones: The existence of fast and slow muscles (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 166 (1980), S. 145-154 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The sea anemones studied have two morphological types of muscle fiber. Types A and B are distinguishable on the basis of myofilament patterns, size of fibers, responses to fixation, and staining with methylene blue. Observation of the muscle in both resting and contracted states has shown that the two types do not result from differences in contraction state of the muscle. The fine structural characteristics distinguishing A and B fibers are similar to those which distinguish fast and slow muscle fibers in higher animals. The distribution of A and B fibers in Stomphia and Aiptasia is consistent with the distribution of fast and slow muscles in these two species. It is proposed that the A and B fibers represent two morphologically distinct kinds of smooth muscle, and that the capacity for fast and slow contraction in the muscles of Stomphia and Aiptasia, and possibly in all actinians, is due to morphological differentiation in the muscle system.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051660203
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  • 100
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    Lymphocyte positions in the dome epithelium of the rabbit appendix (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 166 (1980), S. 179-195 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The apico-basal distribution of lymphocytes within the epithelium covering the domes of lymphatic tissue in the wall of the rabbit appendix was investigated in single and serial sections stained either for general histology, for cytoplasmic basophilia and acidophilia, or for nonspecific esterase activity. From the base to the summit of a dome, four zones numbered proximo-distally 1-4 were distinguished. Epithelial cells migrate from base to summit, as indicated by mitotic figures in zone 1, the gradual change from cytoplasmic basophilia to acidophilia in zones 2 to 4, and visible extrusion of cells from zone 4 at the summit. Zone 1 was free of lymphocytes. Most of the lymphocytes in zone 2 were intercellular and randomly arranged, but a few in this zone were within tapered epithelial cells modified by a process extending basally to the basement membrane. Small numbers of these tapered epithelial cells also occurred in zone 3. The large clusters of ten to 12 lymphocytes that characterized zone 3 were intercellular and impinged the apical regions of epithelial cells. Serial sections at the level of the distal cluster of zone 3 showed lymphocytes located also more basally, and some of these lymphocytes appeared to be passing through the basement membrane back into the lymphoid tissue of the dome. Epithelium of zone 4 over the distal surface of a dome was largely free of lymphocytes. Apparently most infiltrating lymphocytes form intercellular clusters and then return to the subepithelial lymphatic tissue.
    Additional Material: 27 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051660205
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