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  • Articles  (207)
  • Cell & Developmental Biology  (203)
  • Cartilage  (4)
  • 1980-1984
  • 1965-1969  (166)
  • 1925-1929  (41)
  • 1968  (166)
  • 1929  (41)
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  • Articles  (207)
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  • 1980-1984
  • 1965-1969  (166)
  • 1925-1929  (41)
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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 2 (1968), S. 157-164 
    ISSN: 1432-0827
    Keywords: Protein-polysaccharide Synthesis ; Epiphyseal Plate ; Cartilage ; Rabbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Une méthode de séparation des zones cellulaires de prolifération, de maturation et d'hypertrophie de la métaphyse épiphysaire du jeune lapin est mise au point, de façon à pouvoir étudier le métabolisme protéino-polysaccharidiquein vitro sur une base cellulaire. En utilisant l'incorporation de35SO4 comme index de la synthèse protéino-polysaccharidique et la concentration en hexosamine comme index du contenu en protéine-polysaccharide par zone, il apparait que la concentration en sulfate varie inversement avec le contenu en matrice protéino-polysaccharidique: elle est la plus élevée dans la couche des cellules hypertrophiques où le contenu en matrice est le plus bas. La signification possible de ce rapport est envisagée.
    Abstract: Zusammenfassung Es wird eine Methode zur Trennung der proliferativen, reifenden und hypertrophen Zellzonen der Epiphysenwachstumsplatte beim entwöhnten Kaninchen besprochen, die es ermöglicht, den Protein-Polysaccharid-Metabolismusin vitro für jeden Zelltyp gesondert zu untersuchen. Als Index der Protein-Polysaccharid-Synthese wurde die zeitbedingte Aufnahme von35SO4-Ionen verfolgt, während als Index des Protein-Polysaccharidgehaltes der Zonen die Hexosaminkonzentration gemessen wurde. Bei diesem Vorgehen wurde gefunden, daß die Sulfataufnahme entgegengesetzt zum Protein-Polysaccharidgehalt der Matrix variiert, indem sie die höchsten Werte in der hypertrophen Zellschicht auftweis, wo der Matrixgehalt am kleinsten ist. Die Bedeutung dieses Verhältnisses wird besprochen.
    Notes: Abstract A method is presented for separating the proliferative, maturing and hypertrophic cell zones of the epiphyseal growth plate of the weanling rabbit, in such a manner that protein-polysaccharide metabolism could be studiedin vitro on a per-cell basis. Using the timed incorporation of35SO4 as an index of protein-polysaccharide synthesis, and hexosamine concentration as an index of protein-polysaccharide content per zone, it was found that sulfate uptake varied inversely with matrix protein-polysaccharide content; being highest in the hypertrophic cell layer where matrix content was least. The possible significance of this relationship is discussed.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 2 (1968), S. 197-213 
    ISSN: 1432-0827
    Keywords: Ossification ; Epiphysis ; Cartilage ; Mucopolysaccharides ; Growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé La crête iliaque est une épiphyse de traction, où s'insèrent de larges faisceaux de collagène. Chez l'enfant, elle est constituée par une couche importante de cartilage hyalin surmontant une plaque de croissance. Des divisions de cellules chondroblastiques, au niveau du cartilage hyalin et de la plaque de croissance, sont plus nombreuses pendant les deux periodes de croissance rapide du tronc, à savoir l'enfance et l'adolescence. L'ossification enchondrale, identique à celle des os longs, s'observe au niveau de la plaque de croissance de la crête iliaque, entre les régions où se produisent la calcification et l'ossification; elle semble identique à celle qui se produit au niveau de l'insertion de certains ligaments. Un centre d'ossification secondaire apparait au niveau de la partie médiane du cartilage de la crête pendant l'adolescence. L'os se forme, souvent, directement au-dessus du cartilage comme dans le cas de la reconstitution d'une nécrose osseuse aseptique. La concentration en galactosamine du cartilage de la crête iliaque d'enfants normaux décroit brutalement au cours des deux premières années de la vie. Puis elle décroit plus lentement jusqu'à l'âge de neuf à douze ans, pour augmenter à nouveau jusqu'à seize ans. Cette augmentation coïncide avec le début de la croissance de l'adolescence. La concentration en glucosamine reste constante. L'hydroxylproline augmente nettement pendant l'enfance, puis reste inchangée.
    Abstract: Zusammenfassung Der Beckenkamm ist eine Zugepiphyse, an welcher große Bündel von kollagenen Fasern ansetzen. Beim Kind besteht sie aus einer Masse von hyalinem Knorpel, der die Wachstumsplatte überlagert. Die Knorpelzellteilung im hyalinen Knorpel und in der Wachstumsplatte ist während der beiden raschen Wachstumsperioden des Rumpfes in der Kindheit und in der Adoleszenz gesteigert. Die endochondrale Verknöcherung, wie sie in den Röhrenknochen zu sehen ist, nimmt in der Wachstumsplatte des Beckenkammes ihren Verlauf zwischen Zonen in welchen Calcification und Ossification stattfinden, ähnlich jener an der Ansatzstelle gewisser Ligamente. Ein sekundäres Ossifikationszentrum entwickelt sich in der Mitte des Kammknorpels während der Adoleszenz. In manchen Bezirken bildet sich der Knochen direkt über dem Knorpel, indem er diesen ersetzt, ein Vorgang, der auch bei der Abheilung aseptischer Knochennekrosen in Form des sogenannten “kriechenden Ersatzes” beobachtet werden kann. Die Galaktosamin-Konzentration im Knorpel des Beckenkammes normaler Kinder sinkt beträchtlich während der zwei ersten Lebensjahre. Später nimmt sie allmählich weiter ab bis zum Alter von 9–12 Jahren, um anschließend bis zum 16. Lebensjahr wieder anzusteigen. Diese Zunahme fällt mit der Zeit des Wachstumsstoßes in der Adoleszenz zusammen. Die Konzentration des Glucosamins innerhalb der untersuchten Altersgruppe bleibt praktisch konstant. Das Hydroxyprolin nimmt im Kleinkindesalter stark zu, bleibt jedoch später konstant.
    Notes: Abstract The iliac crest is a traction epiphysis where large bundles of collagen fibers insert. In the child it is formed by a large mass of hyaline cartilage overlying a growth plate. Cartilage cell divisions in the hyaline cartilage and in the growth plate are more numerous during both periods of rapid trunk growth, infancy and adolescence. Enchondral ossification as seen in the long bones occurs in the iliac crest growth plate in between areas where calcification and ossification takes place resembling that at the insertions of certain ligaments. A secondary center of ossification develops in the middle of the crest cartilage during adolescence. In many areas bone forms directly over the cartilage, replacing it, resembling the “creeping replacement” observed in healing of aseptic bone necrosis. The galactosamine concentration in the iliac crest cartilage of normal children decreases sharply during the first two years of life. Then, it declines gradually until nine to twelve years of age, and then, again, increases until sixteen years of age. This increase takes place at the time when the adolescent growth spurt occurs. Glucosamine concentration remains nearly constant throughout the age range studied. Hydroxyproline increases sharply during infancy and stays unchanged thereafter.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 2 (1968), S. 253-261 
    ISSN: 1432-0827
    Keywords: Calcium ; Ion ; Binding ; Chondroitin ; Cartilage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé La liaison du calcium par le sulfate de chondroitin C a été étudiée en utilisant des méthodes biologiques et physicochimiques pour la détermination quantitative du calcium ionique. Les valeurs moyennes pour logK j, le logarithme de la constante de formation non corrigée d'un complexe calcium-sulfate de chondroitin C, sont 1,64 par la technique de cœur de grenouille, 1,55 par la méthode de murexide, 1,39 par l'ultrafiltration et 1,04 par l'électrode sélective du calcium. L'ordre de grandeur de ces valeurs suggèrent que le sulfate de chondroitin C a une capacité de liaison pour calcium relativement élevée, mais les valeurs calculées pour un paramètre d'échangeK p indiquent que le calcium a une affinité faible pour le polysaccharide.
    Abstract: Zusammenfassung Die Bindung von Calcium mit Chondroitinsulfat C wurde untersucht mittels biologischer und physikalisch-chemischer Methoden für die quantitative Bestimmung des ionischen Calciums. Im Durchschnitt ergab logK j, der Logarithmus der unkorrigierten Formationskonstante für einen Calciumchondroitinsulfatkomplex, 1,64 mit der Technik des Froschherzens, 1,55 mit der Murexidmethode, 1,39 mittels Ultrafiltration und 1,04 mit den Calciumselektiven Elektroden. Die Größe dieser Werte zeigt, daß Chondroitinsulfat eine relativ hohe Bindungskapazität für Calcium hat, die berechneten Werte für einen AustauschparameterK p jedoch, daß Calcium eine kleine Affinität für Polysaccharide hat.
    Notes: Abstract The binding of calcium by chondroitin sulfate C was studied by employing biological and physicochemical methods for the quantitative determination of ionic calcium. Mean values for logK j, the logarithm of the uncorrected formation constant for a calcium-chondroitin sulfate complex, were 1.64 with the frog heart technique, 1.55 with the murexide method, 1.39 with ultrafiltration and 1.04 with the calcium selective electrode. The magnitude of these values suggests that chondroitin sulfate has a relatively high binding capacity for calcium, but calculated values for an exchange parameterK p indicate that calcium has a low affinity for the polysaccharide.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 2 (1968), S. 214-228 
    ISSN: 1432-0827
    Keywords: Calcinosis ; Calcification ; Cartilage ; Collagen ; Mineral metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Les facteurs, influençant la vitesse et l'intensité du phénomène d'association des ions calcium et phosphates avec des fibres contenant du collagène, et préparés à partir du tendon de boeuf par deux méthodes d'extraction différentes, ont été étudiés. Les fibres, obtenues par ces deux méthodes, nécessitent spécifiquement du phosphate pour absorber du calcium et vice versa. L'absorption ionique des deux préparations est inhibée par du Mg++, du pyrophosphate et un peptide acidique, isolé du sérum humain. Alors que les fibres contenant du collagène, préparées selon les deux méthodes, présentent une absorption ionique à des vitesses sensiblement identiques, seule une des méthodes donne une matrice réagissant positivement à la technique de coloration au nitrate d'argent de von Kossa. Etant donné que les deux critères de calcification sont intéressés de façon identique par des conditions de réaction et par des inhibiteurs, il apparait que les deux facteurs sont des manifestations de différents stades de calcification et que des études d'absorption ionique fournissent une base quantitative d'appréciation de la calcification, pouvant être d'importance pour l'étude du mécanisme et de contrôle de la minéralisation tissulaire.
    Abstract: Zusammenfassung Überprüft wurden die Faktoren, welche Geschwindigkeit und Ausmaß der Erscheinung beeinflussen, wobei Calcium- und Phosphationen sich mit den kollagenhaltigen, durch zwei verschiedene Extraktionsmethoden aus Rindersehnen gewonnenen Fasern eng zusammenbinden. Die mit beiden Methoden zubereiteten Fasern benötigen spezifisch Phosphat für die Calciumaufnahme und Calcium für die Phosphataufnahme. Die Ionenaufnahme beider Arten wird durch Mg++, Pyrophosphat und saure, aus dem menschlichen Serum isolierte Peptide gehemmt. Während die nach beiden Methoden präparierten kollagenhaltigen Fasern eine Ionenaufnahme von beinahe gleicher Geschwindigkeit verursachen, ergibt nur eine dieser Methoden eine Matrix, die mit der Silbernitratfärbung nach vonKossa positiv reagiert. Da beide Calcifikationskriterien gleicherweise durch Reaktionsbedingungen und Inhibitoren beeinflußt werden, wird daraus geschlossen, daß beide Erscheinungen verschiedener Stadien des Gesamtcalcifikationsprozesses sind. Untersuchungen über die Ionenaufnahme ergeben eine quantitative Angabe der Verkalkung, welche für die Erforschung des Mechanismus und der Kontrolle der Mineralisation der Gewebe wichtig sein könnte.
    Notes: Abstract Factors that influence the rate and extent of the phenomenon in which calcium and phosphate ions become firmly associated with collagen-containing fibers prepared from beef tendon by two different extraction methods have been investigated. The fibers produced by both methods specifically require phosphate for calcium uptake and calcium is required for phosphate uptake. Ion uptake by both types is inhibited by Mg++, pyrophosphate, and an acidic peptide isolated from human serum. Whereas the collagen-containing fibers prepared by both methods induce ion uptake at nearly identical rates, only one of the methods produced a matrix that gives a positive response to the silver nitrate staining technique of von Kossa. Since both criteria of calcification are similarly influenced by reaction conditions and inhibitors, it is concluded that both are manifestations of different stages of the overall calcification process and that studies of ion uptake provide a quantitative assessment of calcification which could be of importance for investigating the mechanism and control of tissue mineralization.
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 124 (1968), S. 37-77 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The cells surrounding a wound in the integument of Rhodnius adults show an increase in RNA content, cytochrome oxidase and esterase activity. An excision in the integument is filled by blood which coagulates and is tanned into an insoluble membrane. The basement membrane of the adjoining epidermis acts as a self-sealing membrane and contracts to cover the excision. The epidermis is attached to the cuticle by the subcuticular layer which it resorbs and by pore canal filaments which are left behind as it migrates. The epidermis migrates as a sheet in contact with the cuticle then with the coagulated blood and basement membrane which cover the excision. Blood cells migrate individually into an excision and do not adhere to a surface in the process. Microtubules cannot be identified with movement. Both epidermal and blood cells remove the cells killed by wounding as evidenced by the appearance of coated vesicles and phagocytic bodies in both cell types. The reconstituted integument consists of a surface membrane in which the layers of the epicuticle are not distinguishable, a nonlamellate cuticle secreted by an epidermis which also appears to secrete the new basement membrane.
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  • 6
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    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 124 (1968), S. 295-311 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The development of intraneural vessels was studied in response to an induced hypermorphosis of neural tissue inthe midbrains of 38 chick embryos ranging in age from three days through 14 days of incubation. The pattern of vascularization was compared with that of normal chick embryos at comparable stages of development. In the experimental embryos, the increase in mitotic figures along the ventricular borders of the mesencephalon is accompanied by the establishment of an endoneural plexus approximately one day earlier than is the case during normal vascularization of the midbrain. This plexus also penetrates more deeply and extensively into the ependymal layer. Surface vessels and intraneural vascular elements are dilated, and the cerebrospinal fluid contains varying amounts of blood released from large intraneural vessels which protrude into the ventricle. The most prominent cerebrovascular effects seem to occur between the fourth and eighth days of incubation. Thereafter, the cerebrovascular pattern becomes more normal except for relatively few isolated hemorrhagic areas.
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  • 7
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 124 (1968), S. 345-351 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The eye of Haideotriton wallacei is more reduced histologically than those of othe troglobitic salamanders. The tiny eye is imbedded in a mass of adipose tissue. No extrinsic eye muscles are present. A rudimentary lens is present in about half of the eyes examined. In two instances the lens is surrounded by a small chamber; most eyes lack a chamber. The retina and iris are relatively undifferentiated. The relatively massive retina lacks rods and cones, an outer plexiform layer and subdivided nuclear layers. A tiny optic nerve runs to the brain.
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  • 8
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The aesthetascs, short thin-walled pegs on the antennule flagella of Coenobita clypeatus, a terrestrial hermit crab, are similar to those of other decapod crustacea in containing the dendrites of many bipolar neurons whose cell bodies are grouped in spindle-shaped masses beneath the bases of each hair. The dendrites contain rootlets, basal bodies, and cilia, which divide dichotomously before entering the aesthetasc, so that within the hair, each cilium becomes represented by a group of slender branches.The aesthetascs themselves are short, blunt, and partially recumbent so that each has an exposed and an unexposed side. The cuticle on the exposed side is thinner and more tenuous than that on the protected side, and the dendrite branches are concentrated just underneath. The protected side, on the other hand, is lined with nondendritic supporting cells, and the cuticle is thicker, more lamellar, and probably less permeable.All dendritic elements proximal to the dendrite branches are enclosed within the main body of the antennular flagellum, and the initial segments of the cilia lie within a vacuole. In these respects, the aesthetascs of Coenobita resemble the thin-walled pegs on insect antennae more than they do those of the marine decapods thus far examined. This convergence in the terrestrial forms may be in response to the need to conserve water.
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  • 9
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The Brittle Star digestive system is composed of buccal, pharyngeal, esophageal and stomach cavities. The buccal and pharyngeal cavities are lined by columnar cells covered by a cuticle, and are apparently concerned with mucous production. Coelomocytes and tall columnar cells are described in the esophagus and stomach epithelia. The columnar cells are adapted for nutrient absorption, enzyme synthesis, and lipid storage. Nerves are found beneath the epithelia within a connective tissue layer. Smooth muscle and coelomic layers lie external to the connective tissue layer. The coelomic layer lines a perivisceral space and has diverse modifications of its perivisceral surface; a pedicle-cuticle modification perhaps having general significance in echinoderms.
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  • 10
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 125 (1968), S. 61-70 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Two complete composite photographs of the optic nerve of Limulus, made by electron microscopy, reveal the presence of neurosecretory granules in the large axons of the rudimentary eye neurons. The number of intermediate sized, (3-7 μ), of eccentric cells corresponds with the number of ommatidia as expected, but only their sheath of Schwann cells show an intimate interfolding. Based on the number of fine axons within the nerve each ommatidium has an average of 12-13 retinular cells. The diameter of their fibers is between 0.2 and 3 μ although the majority are between 1 and 1.5 μ. They are aggregated into bundles of six to seven fibers by the sheath cells although some bundles contain only two, others as many as 181 fibers. There is no indication in these studies that retinular cell axons within a bundle are associated with the same, adjacent, or other pattern of ommatidia. The photographs suggest that physiological activity in retinular cell axons might be detected most easily in the smallest bundles because they contain the fewest, but the larger retinular cell axons.
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  • 11
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The lateral and ventral external surfaces of the third and fourth abdominal segments were described and muscle attachments were correlated with surface indentations of the larva. The proleg of this species has a symmetrical planta with a complete circle of crochets. Furthermore, it differs externally from the grasping type of proleg in having a largely membranous coxal region confluent with the body wall, and a relatively large subcoxal lobe.The body wall musculature and innervation of the third and fourth abdominal segments are similar in many respects to those described for other lepidopteran larvae to which they are here compared, but differ from most because of the simpler structure of the prolegs which lack highly developed adductor muscles. Like most muscles innervated by the ventral nerve, the principal plantar retractors of these two segments cease to function in the first day of the pupal stage and have completely degenerated by the forty-fifth hour of pupal life. The ventral nerve retains its four primary branches in the adult, in which many smaller rami can be traced to the cuticle and to the neoblastic body wall muscles.
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  • 12
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The gross anatomy of muscles, the topography of nerve tissues, and the histology of the pregenital abdominal glands of Nomia melanderi Ckll. are reported in detail. The movable and fixed points of muscle attachment were utilized in establishing a system of nomenclature for a typical abdominal segment. Names of nervules correspond to those of the tissues they innervate. The points of attachment of muscles of the fifth abdominal segment are essentially the same in both Nomia and Apis, except for the second tergo-sternal muscle which, in Nomia, has shifted its point of movable attachment to the membranous integument in front of the intersegmental membrane gland where it helps in relasing glandular secretion. The general plan of the nerves in the fifth abdominal segment in Nomia is more diffuse than in Apis, but there is no difficulty in establishing homology between the nervules of the two species. A pair of intersegmental stretch organs was found in abdominal segments 3-6. Glands of the sixth intersegmental membrane possess a reservoir with peripheral pouches both of which are absent in those of the fifth. Both types of glands have neither closing nor opening mechanisms, and neither is innervated. Release of glandular secretion is accomplished by the action of the tergo-sternal muscles.
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  • 13
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 125 (1968), S. 253-257 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This report describes the capacity of larvae of the Leopard frog, Rana pipiens, to regenerate pineal tissue after embryonic pinealectomy, and presents experimental evidence for frontal organ dependence on the epiphysis. In addition, it was found that the “brow spot,” a pigment-free region located in the epidermis betweeen the eyes, is dependent on the frontal organ for its formation. This report also substantiates that the absence of the pineal organ in larval animals does not affect growth or development through metamorphosis.
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  • 14
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 125 (1968), S. 315-328 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Interest in the structure of the antennae of the Florida Queen butterfly arises from the finding that a pheromone is active in their courtship. Light and electron microscopic techniques were used to study the sensilla on the antennae and three types of sensilla with perforated walls were identified. The most common of these are short, thin-walled pegs which are distributed over most of the antennal surface. Long, curved, thin-walled pegs occur in patches on the inner medial antennal surface. Multiple coeloconic sensilla are present having up to 50 pegs in one sensillum. On the outer 28 flagellar subsegments there are two such sensilla per subsegment. In addition there are on the antennae long, thick-walled hairs which are mechanoreceptors and probably also contact chemoreceptors. Sunken pegs, the function of which is not known, occur on the antennae. Grooved sensilla were found with the electron microscope but could not be identified with the light microscope. There was no indication of sexual dimorphism in sensilla types or numbers on the antennae.
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  • 15
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 125 (1968), S. 403-417 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Succinic dehydrogenase, NAD and NADP diaphorases, choline oxidase, d-amino acid oxidase, α-glycerophosphate dehydrogenase, glutamic dehydrogenase, lactic dehydrogenase and aldolase were identified histochemically in the esophagus and proventriculus of the developing chick embryo. In general, the deep glands of the proventriculus reacted more strongly than the epithelium and mucous glands of the esophagus to the tests. The intensity of the enzymatic activity seems correlated with the number of mitochondria and metabolic activity of the cells.
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  • 16
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 126 (1968) 
    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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  • 17
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Two kinds of tactile hairs, plain and wavy, thick-walled chemoreceptors and two types of thin-walled chemoreceptors are present on the antennal flagellum of Gromphadorhina portentosa males. These are described and their location on the antenna noted. Females of this species have plain tactile hairs and the same types of chemoreceptors as do the males but wavy tactile hairs are absent. The antennal sense organs of a few specimens of five other species of cockroaches  -  Periplaneta americana, Blatta orientalis, Supella longipalpa, Pycnoscelus surinamensis and Diploptera punctata  -  were also examined. All lacked tactile hairs but were provided with thick-walled chemoreceptors and with two types of thin-walled chemoreceptors similar to those described for Gromphadorhina portentosa.
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  • 18
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Pulse labeling with tritiated thymidine has permitted the identification of a progenitor cell compartment at the base of the hypostomal glandular ridges of the marine hydroid Podocoryne carnea. This progenitor compartment produces cells which move out on the ridges differentiate as digestive gland cells, and are ejected into the gastro-vascular cavity. Spherous gland cells of the body appear not to be part of this circumscribed replacement system. There appears to be no proximal movement of gastrodermal cells in the body of this marine hydroid.
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  • 19
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Among eight species of mammals in this study (cattle, sheep, pig-tail and rhesus monkeys, rabbit, pig, rat, and dog) four basic patterns of anatomical structure at the uterotubal junction are described. The classification of types is based upon the presence or absence of an intramural portion of the oviduct and of isthmal folds or plicae projecting into the lumen of the uterine cornu.Histological variations are reported for three tissues: epithelial and connective of the mucosa and smooth muscle of the tunica muscularis. In the epithelium during the estrous cycle the differences recorded include: (a) absence of ciliated cells in the distal end of the oviduct in rat and dog; (b) variations in ciliated and nonciliated cells in (1) cell height, (2) location, shape and stainability of the nucleus, and (3) in amount and stainability of apical cytoplasm; (c) presence of lymphoblast-like cells which appear to migrate through the epithelium from the lamina propria. The connective tissue of the mucosa, as a circular layer and as cores for the mucosal folds, shows variations in thickness and in relative density of cells and fibers of the matrix. Emphasis is given to the presence of an inner longitudinal layer of smooth muscle in the tunica muscularis of the distal oviduct in six of the eight species.
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  • 20
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    Journal of Morphology 125 (1968), S. 259-279 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The structure of cells in the colleterial glands of the Cecropia silkmoth was examined. Morphologically and functionally the gland is divided into two regions, a tubular one in which columnar protein-synthesizing cells are located, and an expanded region in which flattened cells with very different structure are most prominent. The fine structure of the latter cells which are presumed to secrete a phenolic glucoside, closely resembles that of cells described in the colleterial glands of orthopterans. The protein-secreting cells have many features normally associated with pancreatic acinar, and other cells of similar function. Among these are extensive rough endoplasmic reticulum, an elaborate Golgi complex, and a modest number of mitochondria. Other features which are less usual in cells of this type are an elaborate secretory apparatus consisting of a cuticular tubule inserted into a microvilli-lined cavity at the apical end of the cell, and large numbers of cytolysomes, myelin figures, and lipid droplets. A chitogenous cell with a very distinct and specific type of ultrastructure is found associated with the secretory cell. This cell type is attached to the cuticular elements of the gland, and the main features of its cytoplasm are extensive bundles of microtubules which presumably serve as supportive elements for the secretory cells.
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  • 21
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    Journal of Morphology 125 (1968), S. 329-365 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Embryonic chick myocardium (stages 8+ to 12-) was studied by light and electron microscopy. The myocardium, which is initially comprised of radially oriented cells with large intercellular spaces gradually becomes more tightly packed. Intercellular spaces decrease and the cells assume a circumferential orientation. Myocardial cells remain epithelial throughout formation of the functional tubular heart and specialized epithelial junctions (apical junctional complex or terminal bars) undergo modification to form intercalated discs. Embryonic myocardial cells contain large amounts of free ribosomes and particulate glycogen, the latter often associated with portions of granular reticulum. Unlike developing skeletal muscle. The amount of granular reticulum contained in the myocardial cell cytoplasm is large and, along with a hypertrophied Golgi apparatus, suggests that these cells may have a secretory function. These organelles persist during the initial period of fibril formation. Myofibrils apparently form from non filamentous precursor material and not by alignment of sequentially synthesized components.
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  • 22
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    Journal of Morphology 125 (1968), S. 379-401 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The characteristic anoline climbing organ consists of a number of lamellar scales, on whose outer scale surface are numerous keratinized setae which contact the substrate. These setae are derived from the Oberhautchen of the epidermal generation, and as such are renewed and shed periodically along with the rest of the epidermal material. The histological development of the setae is described, and modifications of the surrounding elements are noted. The relative lengths of the setae and their congregation to form a pad unit poses certain mechanical problems during morphogenesis, simply in terms of accommodation between the functional outer epidermal generation and dermal core of each lamella. Regression of the dermal core and a distal migration of some cells permits accommodation within the lamella for the distal aspect of the Oberhautchen layer, or free margin. Additionally, changes in the gross shape of the lamella occur throughout the sloughing cycle, and a swelling of the cells of the lacunar tissue results in a gap between the stratum corneum of inner and outer epidermal generations. There is a considerable amount of variation in mitotic activity between the germinal layers of opposite sides of the lamella.
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  • 23
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    Notes: Function and ultrastructure of the excretory organs (antennal glands) of the shore crab Uca mordax were investigated. The crabs were maintained at three different salinities: 50%, 100% and 200% seawater. In spite of previous reports to the contrary, the investigation showed that the powerful osmoregulatory ability found in Uca mordax is not due to participation of the antennal glands. Freezing point depression of urine under all conditions was found to be slightly less than that of the hemolymph, indicating a slightly hypoosmotic urine. It was further found that the antennal gland is extremely effective in resorbing sodium from the filtrate. The higher the salinity to which the crabs were acclimated the lower the sodium concentration in the urine. No water was resorbed from the filtrate as shown by the fact that the inulin U/P ratio remained unity regardless of the salinity to which the crabs were adapted. Electronmicroscopy of the antennal glands revealed that the coelomosac cells are similar to the podocytes described in the crayfish by Kümmel ('64), and the coelomosac appears to be a typical filtration organ. The cells of the labyrinth showed brush border and very elaborate basal infoldings with numerous mitochondria. The deep cytoplasmic infoldings which represent interdigitations with neighboring cells may be correlated with the effective sodium reabsorption in the labyrinth, but apparently not with water movement.
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  • 24
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    Journal of Morphology 126 (1968), S. 31-65 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Mitochondria in early spermatids of many insects aggregate and form a round body, the nebenkern. The nebenkern undergoes a structural differentiation and then divides into two separate equal-sized bodies. In the present study, nebenkerns of Murgantia histrionica, a Hemipteran insect, were reconstructed using electron micrographs of serial sections to determine how the mitochondria transform into the two separate bodies.Newly formed nebenkerns are made of one piece, an anastomosis of rod-like segments. Some segments interconnect to join networks of rings. Each network interlocks with another similar network, but networks which interlock are connected with each other by other segments of the nebenkern. Later, the entire nebenkern is made of two unconnected and interlocked networks of rings. The nebenkern appears to remain bipartite during subsequent differentiation. Since the two pieces are interlocked, breaks must occur before the pieces can separate. As breaks occur, each network transforms into a set of curved sheets, producing a nebenkern made of four concentric layers. The three outer layers are each made of two curved sheets which surround a bipartite central core. The surface sheets meet at a furrow in the surface of the nebenkern; segments in each layer are roughly symmetrical with each other about the plane in which the furrow lies. Rod-like segments join alternate segments. The number of layers then decreases to three, and later, to two. These nebenkerns resemble four-layered nebenkerns, but fewer connections between alternate segments are present. The two pieces constituting the nebenkern probably separate after most of the latter connections disappear. Hypotheses to account for the observed changes in nebenkern structure are presented.
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  • 25
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    Journal of Morphology 126 (1968) 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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  • 26
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    Journal of Morphology 126 (1968) 
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  • 27
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    Journal of Morphology 124 (1968) 
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  • 28
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    Journal of Morphology 48 (1929), S. 253-279 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Technique. This work is based not only on the fixed preparations, but also on fresh cover-slip preparations treated with neutral red or 2 per cent osmic acid for a short time.Golgi elements and fatty yolk. The Golgi elements are hollow vesicular bodies with a distinct osmiophilic rim and a central osmiophobic substance. In the youngest oocyte they form a circumnuclear ring. Gradually the vesicles spread out, grow in size, store up fat in their interior, and give rise to the fatty yolk. On account of their higher refractive index, due to the presence of fat, the Golgi vesicles can be occasionally seen even in the young oocytes without any treatment.Mitochondria. The mitochondrial granules also form a circumnuclear ring and are later distributed uniformly.Albuminous yolk. The albuminous yolk is nucleolar in origin. Early in oogenesis, the nucleous buds off small, homogeneous, and highly chromatic particles in the cytoplasm, which sooner or later disappear. Subsequently, the nucleolus becomes less chromatic and develops vacuolar bodies in its interior, which, becoming vacuolated exactly like the parent nucleolus, migrate into the the cytoplasm. These bodies become more and more chromatic and travel toward the periphery of the egg, where they grow in size. Ultimately they break down into small, homogeneous, and highly chromatic bodies which are the definitive albuminous yolk spheres and which subsequently grow enormously in size.
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  • 29
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    Notes: Maturation of the male germ cells in the rat shows some slight modifications of the typical procedure in sex cells, a distinct and rather prolonged synapsis occurring before synizesis and a confused stage immediately after it. The clumping in synizesis is not extreme. In the mixed strain of rats both twenty-one and thirty-one tetrads appear in the late diakinesis. This procedure in the male resembles the maturation of the oocytes in only two points, the beginning of the process, the deutobroch nuclei, and the end of it when the haploid number of chromosomes take their places on the spindle.
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  • 30
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    Journal of Morphology 48 (1929), S. 493-541 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The cells of the blastoderm which are to form the serosa are two- to four-nucleate; the smaller cells of the embryonic rudiment, uninucleate. The band-like embryonic rudiment encircles the yolk at the equator of the egg. The amnion does not begin to form until after the serosa completely covers embryo and yolk. The epithelium of the midgut arises from cells situated at the tips of stomodaeum and proctodaeum. These cells, though not differentiated from adjacent ectoderm at the time of the invagination, are nevertheless interpreted as part of the preprimordium of the endoderm. In the eighty-four-hour stage a fold of amnion grows over the dorsal side of the embryo, entirely covering it in the course of the next few hours. A portion of the amnion thus forms the dorsal wall of the embryo. At the completion of the amnion the embryo rotates so that its ventral side is directed toward the egg center. The amnion raptures just before the larva begins to feed on the yolk which still remains around it. The serosa is consumed before hatching, which takes place about five and one-half days after deposition.
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  • 31
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    Journal of Morphology 48 (1929), S. 585-609 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The caeca of fourteen bantam fowls have been studied. These fowls ranged in age from six days' incubation to three years after hatching. Between the fifth and sixth days of incubation rectal caeca arise as evaginations from the intestine at the junction of the ileum with the colon. The develoing caeca closely resemble histologically the intestine to which they are attached.The caeca are essentially devoid of content until about the nineteenth day of incubation, but during the remaining days of incubation are gorged with a bluish-gray material similar to that found in the colon. Thus, an early defecatory function is indicated.In general, the proximal third of the caeca remains histologically similar to the intestine, but the distal two-thirds undergoes regression. The latter involves the atrophy of the epithelium and glands, accompanied by the appearance of lymphoid tissue. Much of the lymphoid tissue eventually disappears, to a large extent by atrophy and dissolution of the leukocytes. However, to some extent, lymphocytes develop into granulocytes which escape with other leukocytes into the lumina of the caeca and there disintegrate.Lymph nodules begin to appear in the caeca about one week after the chick hatches. The leukocytes, at least in part, arise in situ from the reticular stroma. Eosinophils arise in certain areas of the tunica propria, and in the earlier stages of their development resemble large lymphocytes, in the cytoplasm of which basophilic, amphophilic, and acidophilic granules are intermingled.
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  • 32
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    Notes: In the ovary of the rat the ova arise by proliferations from the germinal epithelium, all cells of which are potential ova. This proliferation begins with the differentiation of the gonad, and may last as long as 369 days postpartum. The embryonic ovary is filled with ova which pass through the typical maturation phases. This continues until five days after parturition. These ova degenerate, none being found in the ovary of the twenty-day rat. After the fifth day postpartum, nuclear development in the ova changes until, by the twentieth day, no typical maturation phases are present. With the degeneration of the embryonic ova the ovary takes on the adult structure.The ovary of the adult female rat shows a modified type of meiosis in the germ cells, while that of the embryo shows the typical phases, indicating that this is the primitive type, with the modified form an acquired characteristic.Ova in a single rat may show both twenty-one and thirty-one chromosomes.Follicle cells are formed from the cells of the germinal epithelium and, like the sex cells, may have both forty-two and sixty-two chromosomes in a single follicle. The lutein cells also show both forty-two and sixty-two chromosomes in a single corpus luteum. The chromosomes of the lutein cells enlarge with the expansion of the cell to a size greatly in excess of the chromosomes of the somatic cells. The theca interna is derived from the tunica albuginea.
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  • 33
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    Topics: Biology , Medicine
    Notes: Adult sloths (Bradypus tridactylus) were studied by electrocardiography and by light and electron microscopy under normal conditions and under experimental conditions as provided for by injection of 2,4-dinitrophenol (DNP) and ether anesthesia. ECG's of the animals indicated heart rates of 45-71/min, which can be considered as the normal heart rate of the sloth under laboratory conditions. Under normal conditions, the contracted ventricular myocardium of the sloth exhibited (a) a wrinkled sarcolemma, (b) the usual pattern of myofibrils and of sarcoplasmic reticulum, (c) small mitochondria with spiked and branched, often anastomosed cristae, including a few small intramitochondrial dark bodies, (d) an amount of sacrcosomes smaller than the amount of myofibrils, (e) many glycogen granules, isolated, in the form of a chain, or as clusters, in subsarcolemmal, intermyofilamentous and perimitochondrial positions, (f) few multivesicular bodies and (g) large flat sections of the transverse tubular system.Injection of DNP (1 mg/kg) caused tachycardia. With ether anesthesia, the ECG showed monophasic action potential of myocardial injury and prolongation of inter or intraventricular condition. Electrically, the sloth's heart responded to hypoxia as do other mammalian hearts.The administration of DNP produced (a) derangement and reduction in number and length of the mitochondrial cristae, (b) disappearance of spikes, connections between the cristae and, consequently, the honeycombed arrangement, (c) increased matricial space in the center of mitochondria which was often filled with a grayish substance, (d) disappearance of small dark intramitochondrial granules, (e) depletion of glycogen particles and (f) few dilations in the sarcoplasmic reticulum.
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  • 34
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    Journal of Morphology 124 (1968), S. 167-179 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Latex endocranial casts, which may be made without damaging the skull, reveal much of the information provided by a hemisected skull. Examination of drawings of endocasts superimposed on skulls may provide insight into the biological significance of skull and brain morphology. The high degree of cranial flexion and the globose brain shape of Daubentonia appear to be related to the functional demands of its gnawing mechanism. The broad frontal lobes of indriids are correlated with orbital orientation; differences in frontal lobe sulcal pattern suggest greater elaboration of the motor filed for the hand in indriids than in lemurids. Several features of lorisid cranial anatomy are discussed. It is suggested that, as a first approximation, increased splanchnocranial declination in small prosimians results from the necessity of accommodating relatively large eyes in a skull with a relatively small splanchnocranium.
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  • 35
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    Journal of Morphology 124 (1968) 
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  • 36
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    Journal of Morphology 124 (1968), S. 283-293 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In March through April when the oocyte growth in the ovaries of the wall lizard (Hemidactylus) is very rapid, the yolk nucleus continues to persist through various stages of previtellogenesis. This persisting yolk nucleus and associated cell components have been studied with histochemical techniques. The spherical and dense yolk nucleus stains for protein, lipoprotein and RNA. It does not form any close morphological association with the other cell components such as the mitochondria, lipid bodies (L2), spaces or canals, diffuse sudanophilic substance and dense bodies, which are arranged into three zones round the yolk nucleus proper. The mitochondria stain for lipoprotein; the L2 bodies consist of phospholipid; the spaces do not contain any material demonstrable with histochemical techniques; and the ooplasm containing the diffuse sudanophilic substance and dense bodies shows lipoprotein, protein and RNA. Eventually, the yolk nucleus disintegrates, and its substance as well as the other cell components are distributed in the cortical ooplasm of oocytes which are ready to form the yolk bodies.Concepts of the origin, morphology, cytochemistry and function of the yolk nucleus in the oocytes of invertebrates and vertebrates, which have come about recently through the application of cytochemical and submicroscopical techniques, are discussed.
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    Journal of Morphology 124 (1968), S. 353-359 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Symmetrical gaits of 37 breeds of dogs were analyzed. Usual walking and trotting gaits resemble those of other carnivores of similar size and conformation. Only certain long-legged dogs pace - usually at the fast walk or slow run. At the moderate walk, long-legged dogs tend to use lateral-couplets gaits, whereas short-legged breeds tend to use single-foot gaits. Many dogs must turn the axis of the body slightly from the line of travel at the trot to prevent interference between fore and hind feet. The relative duration with the ground made by fore and hind feet is discussed, usual support-sequences of the varicus gaits are presented, and the amount of variation is shown.
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  • 38
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    Journal of Morphology 124 (1968), S. 387-421 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Electron microscope autoradiography was used to study cartilage from regenerating limbs of adult newts, Triturus, after intraperitoneal injections of proline-3H. The labeling in the endoplasmic reticulum, small vesicles, Golgi vacuoles, ground cytoplasm and extracellular matrix was compared during the secretion of radioactive products. The data appear to indicate that a large part of the radioactive secretion probably leaves the cell after having been in only one cellular compartment. Although this compartment may be the endoplasmic reticulum, a considerable amount of radioactivity fluxes through the ground cytoplasm and the possibility cannot be excluded that some secretory components leave the cell directly from the ground cytoplasm. The data appear incompatible with the hypothesis that all the radioactivity seen in the extracellular matrix arrived there via a single pathway involving first the endoplasmic reticulum and then the Golgi vacuoles. It is not, however, incompatible with a hypothesis that a fraction of the radioactive product uses this pathway.
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  • 39
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    Journal of Morphology 124 (1968), S. 249-261 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: An electron microscope examination of the minute bristle organules in the Drosophila eye revealed an organisation characteristic of insect hair sensilla. They were derived from four concentrically arranged cells which were active at the mid-pupal stage in producing the bristle, socket and receptor structures. Two of the cells degenerated towards the end of pupation, the mature organule consisting of a bipolar sense cell and an accessory cell.Growth in length of the bristle was accompanied by a proliferation of longitudinally oriented microtubules which gradually disappeared after maximum growth had been achieved. The breakdown of microfibrillar aggregates, which were also present as transient structures in the developing bristle and showed some correspondence with the longitudinal ridges formed at the surface, may similarly be related to the establishment of cell shape by the deposition of the cuticle which occurred at the same time.
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  • 40
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    Journal of Morphology 124 (1968), S. 313-320 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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    Topics: Biology , Medicine
    Notes: Forty-two unselected ovaries from adult mares were examined histologically, and with histochemical methods for mucins. A considerable part of the surface of the ovulation fossa was directly covered by columnar epithelium, with many ciliated cells. This epithelium, which was distributed mainly on the anterior side of the ovulation fossa, closely resembled the contiguous epithelium of the infundibulum of the oviduct, was frequently folded, and gave rise to short clefts projecting into the ovarian substance. The remainder of the ovulation fossa was covered by non-ciliated, low cuboidal or squamous epithelium, lacking folds or clefts.“Fossa cysts,” up to 6.5 mm in diameter, were observed in the ovarian tissue around the ovulation fossa in 27 (64%) of these ovaries. Both simple and branched, tubular and vesicular forms were present, and all were blind-ending. Their epithelial lining cells, which varied from simple squamous to columnar in type, were frequently ciliated. Many fossa cysts contained secretions histochemically similar to those of the columnar epithelium of the ovulation fossa and infundibulum. Both sialic acidcontaining and neutral mucins were present. It is suggested that these cysts were probably derived by ingrowth from the columnar epithelium of the ovulation fossa. This epithelium may be of müllerian duct origin.
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  • 41
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    Journal of Morphology 124 (1968) 
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  • 42
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    Notes: Light microscopic sections of the adult opossum (Didelphis virginiana) spleen were observed to lack venous sinuses; this primitive mammalian spleen may be classified as non-sinusal in nature. In the spleen of the opossum, the capillary segments of the penicillar arteries lacked ellipsoid sheaths characteristic of certain mammalian spleens.Separating the lymphoid nodules from the surrounding red pulp was a distinct band of vascular tissue, the marginal zone. Arising from the central artery within the lymphoid nodule, vessels of capillary dimension were observed to terminate within the marginal zone and the area between lymphoid nodule and marginal zone. In addition to the vascular channels established by the terminal arterial vessels within the red pulp, the system of vessels within the marginal zone has been implicated as an important intermediate vascular channel within the spleen.
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  • 43
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    Notes: A total of 54 embryos of Chrysemys (Chelonia) and 29 embryos of Aristelliger (Lacertilia) were used in examining septation of the embryonic bulbus cordis. Division of this region of the heart includes a period of cushion or septal primordia formation and a period of physical partitioning. In both reptilian genera, the physical configuration of the early bulbus, the temporal sequence of appearance of the endocardial cushions, the number of major endocardial cushions, the primordia composing the two primary bulbar septa, and the mode of descent of the bulbar septa are strikingly similar. The two genera differ primarily in the pattern of the endocardial cushions and consequently the rotation of the two bulbar septa. In both the turtle and the lizard the aortico-pulmonary septum passes through an angle of about 120° in its descent toward the ventricle. In Aristelliger the aortic septum rotates through an angle of approximately 120°. By contrast, the same partition in Chrysemys spirals through an angle of about 90°. The lesser spiral of this septum in the turtle is interpreted as the result of a decrease in the rotation of distal endocardial ridge 4. The pattern of the two bulbar septa in the turtle appears to represent an advanced phylogenetic feature in terms of the evolution of the reptilian bulbus cordis.
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    Journal of Morphology 125 (1968), S. 71-103 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Oogenesis and the relationships between oocytes and other ovarian tissues have been studied in Sypharochiton septentriones. The ovarian tissues were examined by electron microscopy and by histochemical methods.The sac-like ovary is dorsal, below the aorta, and opens to the exterior by two posterior oviducts. Ventrally, the ovarian epithelium is folded inwards to form a series of plates of tissue, which support the developing ova. Each ovum is attached to a tissue plate by a stalk, the plasma membrane of which is bathed by the blood in the tissue plate sinus. Dorsally, ciliated vessels from the aorta enter the ovary and open into blood sinuses in the top of the plates.After each germinal epithelial cell rounds up to become a primary oogonium, it undergoes four mitotic divisions to give rise to a cluster of 16 secondary oogonia. Of these, the outer ones become follicle cells and the inner ones become oocytes. As in other molluses, the increases in nuclear and nucleolar volume are relatively greatest towards the end of previtellogenesis, when chromosomal and nucleolar activity are most intense. This phase of activity is accompanied by a great increase in cytoplasmic basophilia. Subsequently this basophilia is decreased during vitellogenesis, when chromosomal and nucleolar activity diminish. Fluid filled interstices appear in the cytoplasm during early vitellogenesis. Protein yolk deposition is associated with these interstices, but the lipid yolk appears to arise de novo. The follicle cells do not appear to be directly involved in oocyte nutrition.At times during oogenesis, certain manifestations of polarity can be found in the oocyte. This polarity is based on an apical-basal axis and can be related to the nutritive source of the oocyte, namely the blood which bathes the plasma membrane of the oocyte in the stalk.Numerous granulated cells are present in the ovarian tissue plates and ventral epithelium as storage cells containing lysosomes, and they are capable of phagocytosis and micropinocytosis of extracellular material. A scheme is outlined whereby reserves in these cells may be incorporated into the oocyte cytoplasm. Lysosomal activity is responsible for autolysis of the cells as well as resorption of unspawned ova.
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  • 45
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The postnatal development of the pelage and ventral gland of male Mongolian gerbils ranging from newborn to 86 days of age was studied. The development of the gerbil pelage follows a pattern similar to that observed for other rodents. The length of the dorsal and ventral skin juvenile hair cycle was found to be 26 to 28 days with a 15 to 18 day anagen and a ten to 11 day catagen and telogen. Hair follicles in the ventral gland began growth ten days later than those of the general pelage and secondary follicles budded from the sides of primary follicles. The ventral gland area differed from the general pelage in that it lacked a panniculus carnosus. The ventral gland is a complex of pilosebaceous glands which, in the adult, fill the entire hypodermis. The length and width of the pilosebaceous canals of the gland units are greater than those of the dorsum. The period of telogen of the hair follicles in the ventral gland is very short. The mid-ventral gland of the male gerbil appears to be a secondary sexual characteristic.
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  • 46
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    Journal of Morphology 125 (1968) 
    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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  • 47
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The ultrastructure of lymphatic capillaries in the tail fin of Rana catesbiana larvae was investigated. With the use of a colloidal marker particle (Biological Carbon) the extent that these delicate vessels ramify throughout the fin region was demonstrated. This opaque substance also serves as a marker particle for identification of lymphatics with some degree of certainty at both light and electron microscopic levels. The cytoplasm of the lymphatic endothelial cell is abruptly attenuated beyond the perinuclear region, reaching widths as thin as 300 Å. Lymphatic Anchoring filaments are present, but to a lesser degree than noted for other species studied. Other features of interest include an extensive Golgi complex and electron dense bodies that are surrounded by a smooth surfaced unit membrane. These bodies are somewhat heterogeneous in size (500 Å up to 0.5 μ in diameter) and density. Numerous exit channels are provided by the extensive supply of lymphatics throughout the tail fin region of amphibian larva thus allowing them to serve an important function during metamorphosis. It is suggested that these vessels also act as passageways through which lysed cellular and connective tissue components may be rapidly removed during the process of tail fin resorption.
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  • 48
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The cuticle of Watersipora nigra is at first translucent, but it later becomes black and differentiates into two layers. It is composed, at least in part, of a protein-polysaccharide complex. Calcified parts are three-layered: (1) an outer, cuticular layer, (2) a calcium carbonate skeleton deposited on a matrix of acid mucopolysaccharide, and (3) a “skeletal membrane.” The relationships of these layers indicate that the skeleton is intracuticular. A layer of cuticular material, the “intercalary cuticle” is present in lateral walls, but not transverse walls; it may become calcified in some species. The cuticles of calcified and uncalcified parts of cheilostomes are not necessarily homologous.
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  • 49
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    Journal of Morphology 126 (1968), S. 67-93 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Cell population and neuropile morphology of larval and adult brains of the monarch butterfly, Danaus plexippus plexippus, L., are compared. The larval brain is in continuous transition, the processes of adult brain development being underway from the earliest larval stages. It is characterized by a less diverse population of cells and more homogenous fiber areas than those of the adult. Neuroblasts, which divide to form the neurones of the adult brain, occur either in discrete proliferation centers or scattered among the larval ganglion cells. The larval brain contains, in addition to small homogeneous antennal centers and a distinct larval optic center, rapidly developing adult optic centers, corpora pedunculata, and protocerebral bridge. The larval brain lacks a central body. Major differences between larval and adult brains are clearly related to the increased dependence of the adult upon sensory input from the eyes and antennae.
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  • 50
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    Journal of Morphology 126 (1968), S. 123-161 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Distomus variolosus from Roscoff, France, comprises two sorts, differing in their branchial and gonadal patterns. Their sexual cycle has been followed histologically and micro-anatomically. Gonads begin as clumps of lymphocytes that persist along germinal tracts. Cavitation of the clump, growth of the gonoduct, maturation of the gametes, and elaboration of accessory structures are described. Oocytes develop in a linear series in each ovary; only one or two reach maturity in each gonad. The released egg and subsequent tadpole may be held to the ovary by a “leash” formed of the partially everted outer follicle of the egg. Post-mature gonads deteriorate. Testes disrupt altogether; ovaries may persist as moribund loci of remnant germinal tissue. The sharp right-left hermaphroditism of the zooid appears to combine with a subtler anterior-posterior gradient of sexual determination.
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  • 51
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In a hydrozoan jellyfish, the female gonad is differentiated from a specialized region of the epidermis near the manubrium. Changes in the oocytes during growth and vitellogenesis are described as observed with electron microscopic and cytochemical techniques. Three major types of yolk are formed; these include lipid, glycogen, and membrane-bound granules consisting of both protein and carbohydrate. The latter first appear evident within vesicular and cisternal elements of the numerous Golgi complexes. The orientation and structural variations noted between the endoplasmic reticulum and forming face of the Golgi complexes suggest that the protein component of the yolk granules may be transferred from the cisternae of the endoplasmic reticulum to the Golgi complex where it is joined to carbohydrate perhaps synthesized by the Golgi complexes. Stages in the release of the precursor yolk material sequestered in cisternal elements of the Golgi complexes are illustrated. The presence of coated and uncoated vesicles in the Golgi regions and their possible role in intracellular transport are described and discussed. The presence and possible method of morphogenesis of vesiculate yolk bodies are also described. What appear to represent invaginations of the oolemma extend into the ooplasm and display a special orientation with respect to lamellae of the rough-surfaced endoplasmic reticulum. Intraooplasmic synthesis appears to constitute the major pathway for protein-carbohydrate yolk deposition.
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  • 52
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The dipnoan heart is only in part structurally developed to support a separated circulation in pulmonary and systemic circuits. In the present investigation biplane angiocardiography has been used to describe the extent of such a double circulation and the factors which may modify it in the African lungfish, Protopterus aethiopicus.Contrast injections in the pulmonary vein revealed a clear tendency for aerated blood returing from the lungs to be selectively dispatched to the anterior branchial arteries giving rise to the major systemic circulation. Contrast injections in the vena cava delineated the sinus venosus as a large receiving chamber for systemic venous blood. Contraction of the sinus venosus discharged blood into the right, posterior part of the partially divided atrial space. Contrast injection in the pulmonary vein showed that vessel to pass obliquely from right to left such that blood was emptied distinctly into the left side of the atrium. During contraction the atrial space tended to retain a residual volume in its anterior undivided part which minized mixing.Ventricular filling occurred through separate right and left atrio-ventricular connections. Right-left separation in most of the ventricle was maintained by the partial ventricular septum, the trabeculated, spongelike myocardium and the mode of inflow from the atria. Mixing in the anterior undivided portion of the ventricle during the ejection phase was slight due to a streamlined ejection pattern.The outflow through the bulbus cordis occurred in discrete streams which in part were structurally separated by well developed spiral folds. In the anterior bulbus segment the spiral folds are fused and make completely separate dorsal and ventral outflow tracts. The ventral bulbus channel provides blood to the three anterior branchial arteries. The second and third branchial arteries are large and represent direct shunts to the dorsal aorta. The fourth and fifth branchial arteries are gill bearing and receive blood form the dorsal bulbus channel. The most posterior epibranchial vessels give rise to the pulmonary arteries.
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  • 53
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Sinistral ovariectomy in the Japanese quail resulted in some hypertrophy of the rudimentary right gonad in about 80% of the cases. The hypertrophied right gonads were composed of cords of epithelial origin, fat laden cells and a connective tissue stroma containing masses of lymphocytes. Neither cortical tissue nor germ cells were found in any of the gonads. In some cases regeneration of a testis-like tissue was seen on the site of removed left ovary. This, however, did not alter the effects of ovariectomy on rudimentary right gonad, accessory sex organs, plumage or sexual behavior. Neither Wolffian nor Müllerian ducts exhibited hormonal stimulation in poulards showing hypertrophy of right gonad with exception of the latter in two poulards. Early orchiectomy inhibited growth and differentiation of the cloacal gland. This organ revealed no noticeable stimulation in poulards showing hypertrophied right gonads. Castration produced no significant changes in plumage of males. Similarly, sinistral ovariectomy did not effect the first juvenile, but the second juvenile, adult winter and summar plumages changed to the male type. However, the plumage of some of these poulards began to revert to the female character as early as 10 to 12 weeks following ovariectomy. The behavior of capons and poulards revealed no conspicuous difference and neither showed any masculine behavior. The average weight of adult females was 20 to 30 gm above that of adult males whereas that of capons was above normal males and that of poulards below normal females. The average weight of capons was somewhat above that of poulards.
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  • 54
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    Journal of Morphology 125 (1968), S. 281-301 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Lymphatic tissues of inbred lines of White Leghorn chickens and 20-day embryos (inbreeding coefficient exceeds 95%) were used in the experiments, e.g. line 6 was susceptible, line 7 was resistant, and line 15 I was intermediate in response to the virus. Enzyme reactions were studied in cryostat-cut sections of tissues and in tissue minces by colorimetric procedures. Numbers of isozymes and proteins of lymphatic tissues were resolved by disc gel electrophoresis.Colorimetric tests showed that intensities of lactate, malate, isocitrate and succinic dehydrogenase catalyzed reactions were higher in the bursae of 15 I 20-day embryos than they were in bursae of either line 6 or 7 embryos. Intensity of dehydrogenase reactions of the spleen (15 I embryos) exceeded that found in line 6 and 7 embryos. Intensity of diaphorase reactions in the spleen and thymus was fairly uniform in all lines of embryos. Intensity of DPN diaphorase reactions in the bursae of line 15 I embryos exceeds that found in either line 6 or 7 embryos. Intensity of enzyme reactions leveled off to become fairly uniform in lymphatic tissues of chickens 3-4 weeks post hatching with the exception that dehydrogenase reactions were less intense in the thymus of 15 I chickens.Photodensitometer scans of acrylamide gel columns showed that proteins of line 6 lymphatic tissues combined with less Amido black 10B than lymphatic proteins of either line 15 I or 7 embryos. There was fairly good agreement between concentrations of strong mobility (components 1-9) and weak mobility (components 10-16) in lymphatic tissues of all lines of embryos with the exception that strong mobility proteins were about twice as concentrated in line 15 I bursae. Variable numbers of lactate isozymes were found in the lymphatic tissues of 20-day embryos.
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  • 55
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    Journal of Morphology 125 (1968), S. 367-377 
    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 gonads and epididymides, and an analysis of selected scale characters of six hybrid males presumed to be the result of the natural mating of the all-female whiptail lizard species Cnemidophorus neomexicanus and the bisxual species C. inornatus are presented. The histological appearance of the gonads and epididymides reveals a seasonal cyclicity with respect to the production and storage of spermatogenic elements. On the basis of the limited sample, it is postulated that some abnormality may be present in gametogenesis of these hybrid males which could be related to their chromosomal number. The data on scale characters support the interpretation that these hybrids are intermediate with respect to the parental species.
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  • 56
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In 85 frogs and 29 rats, the entire gastrocnemius muscle was removed. After removal of as much connective tissue as possible, about two-thirds of the remaining muscle was finely minced with a scissors. These minced fragments were orthotopically re-implanted, and the overlying skin was sutured. As the implanted muscle fragments degenerate, new muscle fibers appears in the regenerate. The proportion of connective tissue to muscle is usually greater than normal especially in the frog. Grossly, normal relationships are established with the cut ends of the Achilles and proximal tendons, as well as with the blood vessels and nerves. The total diameter of the regenerated muscle is almost always less than half of that seen in normal muscles. Regeneration of muscle is much more extensive in the rat than in the frog, and it occurs almost twice as rapidly. The histology of the regenerative process is described for both the frog and the rat.
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  • 57
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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    Topics: Biology , Medicine
    Notes: Presumptive myoblasts from the regenerating tail of the lizard plated at clonal density undergo extensive growth giving rise to large colonies. After several days in culture at 31°C some of the cells begin to round up and assume a spherical morphology. The number of rounded up cells increases over the next few days until 50 to 75% of the cells are rounded up. If the cultures are switched to a permissive medium, fusion and differentiation occur. If they are left in a nonpermissive medium fusion does not occur. Instead, the cells stretch out on the substrate and become long and attenuated or broad and strap-like. However, differentiation may continue in some of the cells giving mononucleate cells with cross striations. Autoradiographic studies indicate that the rounded up cells represent a post-synthesis, prefusion population of cells.
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  • 58
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    Journal of Morphology 126 (1968), S. 107-122 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The cervicothoracic musculature of the adult cockroach, Nauphoeta cinerea (Olivier) is described for the first time. The adult thoracic ventral intersegmental muscles are compared with those of the nymph and of the adult cockroach, Periplaneta americana (Linnaeus).
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  • 59
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    Journal of Morphology 126 (1968), S. 199-210 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The thoracic skeleton and musculature of the adult bittacid mecopteron Bittacus strigosus Hagen is described. In its musculature, Bittacus shows only moderate differences from two panorpids (Neopanorpa, Panorpa) that have been studied by Maki ('38) and by Hasken ('39), respectively. Not only are these three genera much alike in their musculature generally, but in all of them, and in Boreus (Boreidae) too, the mesothorax is extremely similar to the metathorax. Functional emphasis (for flight) on either of the two pterothoracic segments has not appeared among neuropteroid insects at the metopteran evolutionary level.Although the “snowfleas” of the genus Boreus possess striking alterations of pterothoracic structure in comparison with other mecopterons (Füller, '54, '55), these are related to their unusual activities and have not, to any great extent, affected the two pterothoracic segments differentially.In terms of thoracic specialization, the overall mecopteran pattern represents a stage somewhat advanced beyond the primitive conditions exemplified by the Megaloptera and certain coleopterous larvae, but one that is in general less highly developed than is charatceristic of such neuropteroid orders as the Siphonaptera, Diptera, Trichoptera, and Lepidoptera.
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  • 60
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The comparative morphology of the gonads and fat bodies of members of 17 genera and 46 species of caecilians (Amphibia: Gymnophiona) is described and analyzed. Comparison is made with the morphology of salamanders and frogs in order to elucidate evolutionary trends and relationships within the order Gymnophiona and within the class Amphibia. The structure of the testis lobes and transverse and longitudinal ducts is described based on gross dissection and histological investigation. The pattern of spermatogenesis and interstitial tissue changes are described and compared with those of other amphibians. A trend toward fusion of testis lobes is analyzed. The characteristics of the seasonal reproductive cycle of male Gymnopis m. proxima are described, and evidence for cyclic reproductive activity in other forms is presented. The morphology of the ovaries and ova is described. Size of ovary and size and number of ova is dependent on the state of maturation of the ova. Some evidence for seasonal ovum production and breeding is presented. Fat body morphology is found to be correlated with size, nutrition, and gonad condition, as in other amphibians.
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  • 61
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    Journal of Morphology 126 (1968) 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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  • 62
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The distribution of carbohydrates, proteins, and lipids was studied in the cochleae of kangaroo rat, gerbil, and guinea pig using both fixed paraffin sections and fresh-frozen cryostat sections. Enzyme distribution in the cochleae of the three speices was studied with both EDTA-decalcified and undecalcified fresh-frozen cryostat sections.Although the cochleae of the three species are morphologically different, their distributions of proteins, carbohydrates, and lipids are similar. The zona pectinata of the basilar membrane - which is hypertrophied in the kangaroo rat and gerbil but normal in the guinea pig - stains the same in all three species. The unique, flaskshaped Hensen cells of the kangaroo rat contain more protein than do the normal Hensen cells of the gerbil and guinea pig. At least some of the protein in the kangaroo rat Hensen cells is in the form of carboxylic esterases which are not affected by 10-4 M eserine, but are inhibited by 10-2 M eserine and 10-6 M E600. More than one population of carboxylic esterases is indicated by this reaction to inhibitors and by the results of enzyme distribution tests which used different substrates. A high concentration of malate dehydrogenase in the kangaroo rat Hensen cells may be related to the synthesis of carboxylic esterases. The possible role of these esterases in cochlear functioning is discussed.
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  • 63
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This report presents light microscopic descriptions of normal histology, including innervation, of the lymph glands and jugular bodies, of larval and adult Rana catesbeiana. A brief description of two other adult organs, the propericardial and procoracoid bodies, is also included. The parenchyma was studied by employing the May-Grunwald-Giemsa staining technique for better cytoplasmic differentiation; the Periodic Acid-Schiff technique and hematoxylin and eosin yielded clearer nuclear and cytoplasmic delineations. The intercellular portion of the stroma was studied from sections stained with Masson's trichrome, Weigert's elastic stain, Periodic Acid-Schiff and Wilder's reticulum stain. Demonstration of phagocytes was facilitated by intraperitoneal India ink injections followed by the above staining procedures. Innerrvation was observed in serial sections of silver impregnated whole organs as well as in the other serial sections. These organs are lymphocytopoietic and to a certain extent granulopoietic; they also serve, like the spleen, as graveyards for dead cells and most probably play a role in immunity especially in the synthesis of antibodies as indicated by the presence of plasma cells, macrophages and lymphocytes.
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  • 64
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    Journal of Morphology 47 (1929), S. 89-133 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: During the telophases each chromosome becomes inclosed in an individual sac or vesicle which, together with its contents, is called a chromosomal vesicle. The vesicular membrane is of cytoplasmic origin, but is formed under the influence of the chromosome and a droplet of karyolymph. A precise numerical correspondence between chromosomes and chromosomal vesicles has not been established, but it is evidence that most, if not all, of the chromosomal vesicles retain their individuality during the resting stage and until after the new chromosomes have been fully formed.The transformation of the telophase chromosome into the reticulum of the resting stage and the manner in which a new chromosome is formed from a portion of this reticulum are described in detail. In the early prophases each developing chromosome is embedded in a sheath or matrix of less deeply basophilic material, which disappears before the middle prophase is reached.The formation of chromosomal vesicles is interpreted as a device for doing more rapidly and effectively, under stress of special circumstances, the work that the nucleus must accomplish during the so-called resting stage.
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  • 65
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    Journal of Morphology 47 (1929) 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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  • 66
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    Journal of Morphology 47 (1929), S. 283-333 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The significance of the ultimobranchial body has been the object of a comparative study of the structure in twenty-four species of urodeles. In nineteen of these it has not hitherto been described.Caudal to the last branchial arch, it develops as a thickening and later as an outpushing from the ventral wall of the pharynx. Due to the growth mechanics of the region, it comes to lie obliquely to the pharynx, ventral to it, and dorsal or dorsolateral to the pericardial cavity in its anterior region. It persists throughout life as an epithelioid or epithelial structure, usually of irregular shape, frequently containing vesicles; in some cases it exhibits a considerable amount of secretory activity of variable quality. Except in Amphiuma and Necturus, where it is regularly paired, and in occasional instances in individuals of other species, where it occurs on both sides, it is usually present on the left side only. Its occurrence is constant in all of the species of urodeles for which it has been examined.It is variable in size, form, and position. This, together with the quite inconstant indication of secretory activity, marks it as a structure of little or no physiological significance. ‘Colloid’ is, however, present in some instances, and hence a comparison with the thyroid was considered.
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  • 67
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    Journal of Morphology 47 (1929), S. 435-478 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The perivisceral fluid of Pheretima indica (Horst) contains five types of leucocytes: lymphocytes, monocytes, granulocytes, lamprocytes, and linocytes. The granulocytes differentiate either from free lymphocytes, from peritoneal epithelial cells lining the leucocytopoietic organs, or from lymphocytes (hemocytoblasts) embedded in these organs. The lymphocyte is a hemocytoblast. The eosinophilic granulocyte is the most numerous of the several types of granulocytes. Morphologically and tinctorially, it resembles the eosinophil of fishes. The eosinophil granule is thought to arise either by a ripening of a basophil granule and to pass through a metachromatic phase during this process, or by being formed immediately without such a ripening process in small hemocytoblasts. The stimulus for the excessive production of eosinophils is thought to be the degree of infection of the leucocytopoietic organs by a species of the gregarine, Monocystis.A series of segmentally arranged leucocytopoietic organs is described for the first time in the oligochaetes. These organs are essentially foldings of the septa and offer sacculations in which leucocytopoiesis may take place.A discussion of the possible phylogeny of the hemocytopoietic organs of the invertebrates and vertebrates is given.
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  • 68
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    Journal of Morphology 47 (1929), S. 555-587 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The germ cells of Lebistes are found in cysts; the younger cysts are toward the cortex. Mitochondria and Golgi apparatus are present. During maturation leptotene, bouquet, pachytene, and diakinesis figures are seen. The spermatocyte chromosomes number twenty-three; an X-Y pair is probably present, though the evidence is not conclusive. In spermatid formation the centriole divides to form a rodlet and an axial filament; the nucleus segregates into two materials, one of which is extruded; the remainder first contracts to a cup, comes in contact with the rodlet, then again forms a sphere. The mitochondria are arranged along the proximal part of the axial filament; the sphere flattens and elongates; the rodlet sinks into the head substance and is enfolded by it. The Golgi remnant is sloughed off with the residual cytoplasm, which disappears at the same time the Sertoli cells show an increase in size, suggesting their ingestion of the spermatid remnants. The mature sperm form spermatozeugmen, which are stored in the testicular canal; they are transferred to the female by aid of the modified anal fin.
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  • 69
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    Journal of Morphology 48 (1929), S. 81-103 
    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 of the embryology of the rabbit in races of large and small adult size shows a consistently more rapid rate of cell multiplication and of increase in mass in large-race embryos than in those of small race.This more rapid rate of growth is transm tted by and influenced equally by sperm and egg cell, as is shown by the results of reciprocal crosses.Rate of differentiation is independent of rate of growth and unaffected by it. Consequently, embryos of the large race have attained greater size than those of the small race at corresponding stage of differentiation.The fundamental difference in rate of growth is already in evidence in forty-eight-hour embryos and becomes increasingly clear at later stages. Embryos produced by the large race have undergone about one more cell division at forty-eight hours after mating and so are approximately in the thirty-two-cell stage when embryos of the small race are in the sixteen-cell stage.
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  • 70
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    Journal of Morphology 47 (1929), S. 135-199 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Definite information concerning the time of development and location of the different imaginal discs of Drosophila melanogaster was needed in order to interpret especially the gynandromorphs, mosaics, and intersexes that have been extensively reported in cultures of this fly. This information was also desirable for many of the mutant types. It was not known, for example, when an organ was reduced or absent, whether its imaginal disc showed a corresponding reduction, or whether it was full size in the larvae and pupae, and failed to carry through to the later stages.Three mutant types with eyes smaller than those of the wild type, namely, lozenge, bar, and eyeless, were examined. It was found that there is a corresponding difference in size as far back as the imaginal disc could be detected. Similarly for the two mutants, vestigial and no-wing. Conversely for the mutant, bithorax, in which the metathorax is larger than the normal and has assumed many of the characters of the normal mesothorax, the imaginal disc was correspondingly enlarged.It follows that the effects of the mutant genes for these characters can be observed in the very earliest condition of the imaginal disc.
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  • 71
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    Journal of Morphology 48 (1929), S. 45-79 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: It was found that thyroid deficiency in the albino rat (Mus norvegicus albinus) is followed by a trend to increased concentration of epinephrin in the suprarenals. The basis of this lies in the relatively greater retrogression of the cortex as contrasted with the medulla which becomes a relatively greater proportion of the organ as a whole. Confirmatory evidence is found in cell counts per unit area and the part of the disappearance of lipoid from the cortical cells of the suprarenals of thyroidless animals.
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  • 72
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    Journal of Morphology 48 (1929), S. 123-151 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: From a study of over 1000 mothers, the female chromosome number appears to be 2N = 22; N = 11. The male number has not been exactly determined, but is presumably not haploid. Only one maturation division occurs in the parthenogenetic egg, and the authors have seen only one in the sexual egg. During the growth stages of the eggs, the chromatin is totally obscured by a large amount of deeply staining nucleolar material which exhibits several phases. Ultimately, this material is apparently absorbed into the ooplasm. Just before the egg is laid, the ovoid chromosomes, in late prophase or in metaphase, are seen in a germinal vesicle situated always at one side of the egg. The maturation division occurs immediately after egg laying. A degenerate body, hitherto undescribed, is noted in the ripe parthenogenetic egg, situated at the pole opposite the germinal vesicle. It is believed to arise by reorganization of nucleolar substance. The body in the sexual egg desribed by Weismann and Ishikawa ('91) as the Paracopulationzelle is noted and its interpretation by these authors questioned, but, for lack of sufficient evidence, no counter-explanation is offered. The possible relation between experimental sex control and the time of maturation division in the parathenogenetic egg is discussed.
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  • 73
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    Journal of Morphology 47 (1929), S. 37-87 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The vesicular nucleus of this amoeboflagellate is similar in structure in both phases of its life-cycle. It has a fairly large caryosome surrounded by a pericaryosomal area in which there are small oxyphilic pericaryosomal granules on a fine reticulum. On the inner surface of the definite caryotheca is a layer of epithecal chromatic granules.Nuclear division is similar in both amoeba and flagellate phases. During the prophase the nucleus enlarges, and the expanded caryosome becomes resolved into basophilic and oxyphilic components and assumes either an oblong, dumb-bell, or spindle shape. The pericaryosomal granules enlarge, shift about, and eventually become arranged in an equatorial band around the elongated caryosome. In the metaphase the equatorial plate of chromosomes appears after the inward migration of the pericaryosomal granules, accompanied by the formation of a definite intranuclear spindle, usually with polar masses, polar granules, and a centrodesmose. After the poleward migration of the daughter plates of chromosomes in the anaphase, the telophase constriction of the nuclear membrane produces two daughter nuclei with a portion of the spindle remaining outside. The epithecal layer of granules remains in place on the nuclear membrane during the entire process of mitosis. Plasmotomy normally follows mitosis, but may be delayed, giving rise to multinucleate individuals. In the flagellate the blepharoplast usually divides simultaneously with, but independently of, the nucleus. There are many divergences in the details of mitosis, but these are thought to be variations of one type of division rather than examples of different processes.
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  • 74
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    Notes: In sections the protoplasm of the spinning gland of Platyphylax designatus Walker appears to be a syncytium with large, branching nuclei, which contain both nucleoli and chromatin granules embedded in a delicate linin reticulum.In the normal gland the nucleus is sharply marked off by a nuclear membrane from the granular, homogeneous cytoplasm. The Golgi apparatus appears as rings, loops, or comma-like structures, evenly distributed and without orientation to the nucleus or lumen of the gland.The nucleoli first increase both in number and size within the nucleus, then migrate out into the cytoplasm, where they undergo further growth, and finally are dissolved and passed out into the lumen of the gland as liquid secretion.Small vacuoles appear near the periphery of the gland in early periods of activity.In glands active for forty-eight hours all stages of the secretory process may be seen.In glands active for longer periods only vacuoles are present which we interpret as the remains of the secretory inclusions. There is a progressive decrease in the nuclear content of the nucleus.Throughout the activity of the gland the Golgi apparatus changes little from the normal condition, both in form and distribution. As activity progresses, the bodies become smaller and slightly more dispersed. No relation of Golgi apparatus to the secretory phenomenon is apparent.
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  • 75
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    Journal of Morphology 47 (1929), S. 415-433 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The diploid number of twenty-six chromosomes was found in the mature parthenogenetic female-producing eggs and also in the somatic cells of the female embryos developing from such eggs. In the maturation stages of a few of these eggs the chromosomes were markedly larger than in the corresponding stages of the majority of the eggs. Whether this size difference of the chromosomes is correlated with male- and female-producing individuals has not been determined. The mature parthenogenetic male-producing eggs contain the haploid number of thirteen chromosomes, and this number was found also in the somatic cells of the young male embryos. The mature sexual eggs contain thirteen chromosomes.In spermatogenesis the secondary spermatocyte divisions are usually omitted and the secondary spermatocytes develop directly into the motile spermatozoa containing thirteen chromosomes. A few, however, of the secondary spermatocytes divide, forming spermatids containing fewer than thirteen chromosomes. These cells develop into the non-motile and rudimentary spermatozoa.The motile spermatozoa containing thirteen chromosomes unite with the parthenogenetic male-producing eggs containing thirteen chromosomes, thus producing the fertilized eggs with the diploid number of twenty-six chromosomes. These fertilized eggs develop into female-producing females which reproduce parthenogenetically.
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    Journal of Morphology 47 (1929), S. 519-529 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The liver has a rhythmic function with alternating assimilatory and secretory stages. The height of the assimilatory stage in rabbit's liver is characterized by the following qualities: All the cells are usually expanded and contain much glycogen and few bile components. The bile capillaries are narrow and generally empty. The glycogen content is high (about 13 per cent); the total glycogen weight is also high (about 17 grams). The liver has a relatively heavy weight (about 140 grams), a large volume, notably firm consistency, and a light brown color.The secretory stage at its height has the following characteristics: All cells are shrunken and are rich in bile components, but contain little glycogen. The bile capillaries are expanded and filled with secretion (fixation with barium chloride). The glycogen content is low (about 1 per cent), and the total glycogen weight is also low (about 1/2 gram). Weight of liver low (about 50 grams). Volume small and consistency fairly flaccid. Color dark reddish brown.Between these two extremes are various intermediary stages. Such variations as these probably occur during the normal functioning of the liver in man and also in other animals.
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    Journal of Morphology 48 (1929), S. 1-43 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The parenchymal cells in the parathyroids of Rana catesbeiana (Shaw) are found to undergo a very curious cyclic change. The cytoplasm is broken down by a process of cytolysis. The nuclei are decomposed by chromatolysis and pycnosis. The entire parenchyma is finally liquefied, except for a layer of cells lining the capsule.The parathyroid body is reconstructed by young cells which are produced from rather definite growth centers. The process of regeneration begins some time before cytolysis is completed and continues until the entire organ is restored.The cytolytic and regenerative processes transpire in such sequence that the amount of apparently healthy tissue present at any one time is a rather large portion of the total mass normally present.The relationship between the parenchymal tissue and the stroma of the parathyroid is described.
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  • 78
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    Journal of Morphology 48 (1929), S. 153-171 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A description of the gross embryology of the sex apparatus of a common diplopod, the corn millipede. The life-cycle of this animal involves eleven instars extending over a period of three years.In the male the true first legs are shed at the ninth ecdysis and the large clasping appendages are substituted through the last three instars. In the region of the second body somite the fused coxal plate and the penes are developed at the final molt; the second appendages are reduced at this time. The greatest changes occur in the region of the seventh somite, where the legs are shed about the eighth ecdysis and the gonopods developed through the remaining instars. It is evident that these gonopods arise as a modification of the sternites of the seventh somite.In the female the second legs are reduced to vestiges at the final molt. The structures at the mouth of the oviducts are developed from the surrounding tissues and the modified sternites of the reduced second legs. These changes are in progress as early as the seventh instar, but the greatest changes occur at the final ecdysis.
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    Journal of Morphology 48 (1929), S. 281-316 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The arterial system of Uromastix hardwickii retains many primitive features and shows great resemblance and relationship to that of Sphenodon. The heart is typically reptilian. Two systemics and a pulmonary arch arise from the ventricle. The conus arteriosus is absent. The carotids arise together from the right systemic by means of a small common carotis primaria. A very well-developed ductus caroticus connects each carotid with the systemic arch of its side. The ductus arteriosus (ductus Botalli) is absent.The dorsal aorta is formed by the union of both the systemic arches. The left systemic joins entire while the right one, which is termed systemicocarotid trunk, gives off the carotids, the vertebral, a single subclavian, and two pairs of parietal arteries, before the union. Anterior epigastric arteries are altogether absent. The dorsal aorta gives off fifteen pairs of parietal arteries which are segmentally arranged. All the main branches supplying the alimentary canal and other viscerala organs arise independently of one another, there being no such combination as is found in Varanus.
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    Notes: The rate of locomotion in Amoeba proteus is dependent upon the nature of the substratum, the nature of the different divalent and monovalent cations present, and the ratio of the amount of the monovalent cations to the amount of calcium or strontium. Calcium is more efficient than strontium in antagonizing potassium. Magnesium and barium do not antagonize potassium. The four monovalent cations studied in antagonizing calcium are efficient in the following order: Na〉K〉Li〉Rb. Calcium and potassium are more effective against antagonistic cations when combined with chlorine than when combined with phosphate.
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  • 81
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    Journal of Morphology 48 (1929), S. 543-561 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The parietal fossa or pit is situated in the middorsal line between the ear capsules. From its floor four (sometimes only two) apertures lead into the ear capsules. The anterior apertures are the foramina of the endolymphatic ducts; the posterior ones are the fenestrae. Through the fossa each endolymphatic duct passes from its formen to its external aperture in the dorsal integument, describing in its course a loop with the convexity directed anteriorly. The part of the duct involving the loop is enlarged into an endolymphatic pouch. Into the angle of this loop a small muscle is inserted which is a continuation of the anterior trunk muscles, or one taking a more lateral origin from the edge of the fossa. The fenestra may or may not be closed by a definite fenestral membrane. The posterior semicircular canal (posterior utriculus) bears a peculiar relation to the fenestra. The endolymphatic pouch, like the sacculus, contains otoconia, and sometimes siliceous sand grains. Various functions have been assigned to the endolymphatic organ. There is no convincing experimental evidence as to its significance.
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  • 82
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    Journal of Morphology 48 (1929), S. 611-625 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: By the use of a new technique it was possible to demonstrate the Golgi granules about the idiosome of spermatids and in the so-called Golgi bead of the mature spermatozoon. Other osmiophile granules in the cytoplasm, assumed to be Golgi granules, aggregate during metamorphosis into groups which formed neutral fat spheres, giving stains with both sudan III and scharlach R. Evidence is adduced supporting the view that the Golgi apparatus is a lipin and probably a phospholipin. The fat spheres produced are probably a result of fatty degeneration in the residual body of the spermatid. They may also serve as the source of lipin in Popa's ‘Lipo-gel’ phenomenon.
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  • 83
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    Journal of Morphology 124 (1968), S. 23-35 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The structure and cell types of the closely similar glands of Calamoichthys and Polypterus are described and a general comparison made with the teleost pituitary. The Polypterine gland shows some unsual features in the anatomical disposition of its parts and in the arrangement of its neurosecetory and vascular supply and an explanation of these differences is suggested, based on relative growth changes in later development, in order to include these glands in the evolutionary pattern of the actinopterygian pituitary.
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    Notes: About 10,000 sense organs are present on one antenna of a female mantis, Tenodera angustipennis, and nearly 40,000 on that of a male. These are of four kinds: (1) thick-walled pegs, (2) short thin-walled pegs, (3) medium length thin-walled pegs and (4) long thin-walled pegs. All have the structural characteristics of chemoreceptors. The dendrites of the sensory neurons of the thick-walled pegs are exposed to the air in an opening at its distal end and those of the thin-walled pegs terminate at many pores in the surface. The significance of the larger number of sense organs possessed by the male is discussed. No important differences were found between the antenna of Tenodera angustipennis and those of T. aridifolia and T. australasiae.
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    Journal of Morphology 124 (1968), S. 143-165 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Light and electron microscopical studies allow a descriptive account to be given of the preadult development of the ovary of Drosophila melanogaster. The lineage of the cell groups which contribute to the tissues of the adult ovary has been determined. The earliest morphologically detectable event in the differeentiation of each ovariole is the formation during the larval period of its terminal filament. Oogonia play no role in the induction of terminal filaments. The developmental events which transform a spherical mass of ovarian cells into a collection of multicellular cylinders is described. The importance in morphogenesis of acellular membranes secreted at the interface separting cells of different prospective significances is stressed. Such membranes may serve to regulate the future migration of cell populations or as sites of attachment for monolayers of cells which later fuse to form multinucleated muscle sheaths. The transformation of oogonia to cystoblasts coincides with and presumably depends upon the same hormonal stimulus which causes metamorphosis. The first oocytes to undergo crossing over do so between 24 and 36 hours after puparium formation.
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    Journal of Morphology 124 (1968), S. 217-225 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A morphological study of the presoma of adult Corynosoma hamanni (Linstow, 1892) was undertaken in an effort to clarify some problems encountered during analysis of a large collection of juveniles of this species assembled from fishes of McMurdo Sound. This study is based on approximately 600 adult specimens recovered from four Weddel seals, Leptonychotes weddelli, collected at McMurdo Sound.Morphologically the proboscis armature is more varied than previously reported and consists of 18 to 23 longitudinal rows each with 11 to 15 hooks of two distinct types. At the apex of the proboscis is an undivided, bi-nucleated apical organ unlike that described for species of Neoechinorhynchus. In the basal third of the proboscis is a thin-walled vesicle which extends into the anterior quarter of the proboscis receptacle. The more posterior of two external folds on the presoma is a cuticular invagination permitting recognition of the neck-trunk border of C. hamanni. Lemnisci originate between the two folds and extend into the trunk cavity between the body wall and extensive neck retractor muscles. Contrary to Linstow's original description, each lemniscus is a single structure.Several limitations in material prevent speculation at this time about the limits of intraspecific variation in C. hamanni.
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  • 87
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    Journal of Morphology 125 (1968) 
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  • 88
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    Notes: The formation of cortical alveoli and yolk has been investigated in the pipe-fish, Syngnathus fuscus, and the killifish, Fundulus heteroclitus by techniques of light and electron microscopy. In addition to cortical alveoli and yolk components the ooplasm contains many mitochondria, numerous Golgi complexes, copious quantities of the endoplasmic reticulum of the rough variety, ribosomes and particulate glycogen. While the formation of cortical alveoli and yolk may proceed simultaneously, the cortical alveoli are the first to develop. Staining procedures indicate that cortical alveoli, like some of the yolk bodies contain a polysaccharide component and protein. It is suggested that the protein portion is made by the endoplasmic reticulum and is subsequently transferred to the Golgi complex via vesicles. Within the saccules of the Golgi complex the polysaccharide component is fabricated after which time the Golgi produce vesicles containing the products of either the cortical alveoli or yolk bodies.The precursors used in the production of the yolk are produced by the oocyte (endogenous) and by an organ other than the ovary (exogenous). The precursors made exogenously become associated with the morphologically and physiologically specialized oolemma and are subsequently internalized by the process of micropinocytosis.
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    Journal of Morphology 125 (1968), S. 129-143 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In a variety of amphibians examined the stratum corneum was one cell in depth, although in Xenopus it was up to three cells deep. The flattened horny cells were closely fused together along their lateral membranes to form a continuous sheet. Disulphide bonds of keratin were most concentrated in the peripheral cytoplasm, but the interiors of the cornified cells were sufficiently well keratinized to prevent more than slight enzymatic cytolysis of the normal cell components. Characteristically large, weakly stainable, non-shrunken nuclear remnants were found in the salamander and frog horny layers, but the clawed toad had small pyknotic (parakeratotic) nuclei. The mature amphibian keratinocytes contained free fats, bound phospholipids, calcium and sulphydryl groups, together with acid phosphatase and non-specific esterase. Cornification appears to begin by a process of separate individual cell keratinization and lateral membranes of neighbouring cells only later become fused together. This differs from the process in higher vertebrates in which the cells undergoing keratinization form a uniform transitional layer in the epidermis. In the amphibian epidermis neighbouring cells occur in different stages of keratinization.
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  • 90
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    Notes: The oocyte-nurse cell complex of the polychaetous annelid, Diopatra cuprea, has been explored by various methods of light microscopy and by the technique of electron microscopy. Early in its development the complex appears as a string of cells floating within the coelomic cavity. As this string of cells develops, the volume of one cell (approximately the middle one) increases greatly; while that of the remaining cells, referred to as nurse cells, increase slightly. Due to this differential growth, the two opposing strands of nurse cells are displaced to one side of the oocyte.Nurse cells are joined to one another by cytoplasmic bridges. Cytoplasmic bridges also exist between the strands of nurse cells and the oocyte. The presence of numerous ribosomes within the bridges between the oocyte and nurse cells encourages us to suggest that this organelle may be transferred to the oocyte via this route. The transported ribosomes may be used by the maturing oocyte, or they may be stored by the egg to be utilized during embryogenesis. Moreover, we believe that the nurse cells are not involved in the production of the protein-carbohydrate yolk bodies for we think that these are elaborated by the endoplasmic reticulum in collaboration with certain Golgi complexes of the oocyte.
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  • 91
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    Notes: A series of nine features of the shoulder girdle, chosen as having functional significance in relation to the movements of the shoulder in arboreal locomotion, have been studied in 1188 specimens of 194 genera of mammals. The features were defined metrically and examined by means of a multivariate statistical technique: viz. canonical analysis. The study has shown that those mammals which are nonarboreal differ considerably among themselves and form the arboreal forms. But the myriad shapes of the shoulder girdle in a wide range of mammals (e.g. some marsupials, edentates, rodents, carnivores and primates) which climb or forage in trees, can be summarized mathematically by a very small number of similar canonical variates. This information correlates well with that of a previous series of studies carried out on the primates alone.The biological information that was postulated as being reflected by the individual canonical variates for the primates is also apparent for the arboreal mammals. The different variates separate the forms in ways which are consonant with what is known about the function of the shoulder in locomotion. Aspects of the shape of the shoulder defined by the analysis appear to be discernible from an examination of the contribution of the original variables to each individual canonical variate. This seems to confirm that the shape of the shoulder girdle within a very wide range of mammals is limited by a very small number of underlying factors of biological significance.One interpretation of the results suggests that the genetic model of the mammalian shoulder may have been sufficiently fixed at an early stage in the evolution of the class as to place considerable constraints upon the subsequent evolution of the shoulder in the different Orders.
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    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Hypophysectomized adult newts exhibited 98% survival and limb regeneration at 23 days post-hypophysectomy when injected intraperitoneally every other day with prolactin (0.015 U/newt) and kept continuously in aquaria with 1 × 10-7 concentration of thyroxine. Thyroxine alone was no more effective than saline injections.Prolactin (1.2 U/newt every other day) alone increased survival and limb regeneration, but less effectively than did the prolactin-thyroxine combination.
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  • 93
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 126 (1968), S. 435-445 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Thin semi-serial ground sections of coronal dentin were examined radiographically. The bulk of the coronal dentin was characterized by the majority of the tubules having a distinct peritubular zone. With the exception of the tubules running from the tip of the cusp to the pulp cornu, the bulk of peritubular matrix forming the walls of the tubules was disposed eccentrically. The matrix was thicker on the cervical sides of the tubule than it was on the incisal sides. In a relatively narrow layer of the coronal dentin between the bulk of the dentin and the predentindentin border area the thickness of the peritubular matrix varied considerably. It was extremely narrow or absent in some tubules and reached its greatest thickness in others. The tubules in the predentin border area showed little or no evidence of peritubular matrix. The area of dentin beneath the central developmental groove differed somewhat from the bulk of the dentin. Many of the tubules at all levels of this area showed little radiographic evidence of peritubular matrix. Obliterated tubules were seen in some of the sections taken immediately above the predentin-dentin border area in the region of the pulp cornu and were always seen at the junction of the mantle dentin and the circumpulpal dentin beneath the central developmental groove.
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  • 94
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Microscopic studies of human adrenal glands from 58 autopsy specimens, ranging in age from one month gestation to 69 years, revealed a pertinent developmental pattern in the establishment of definitive zonation. This pattern was established using the following criteria: (1) relationship of age to the developing zones; (2) times of formation of definitive zonation; and (3) the morphological determination of developmental patterns based on staining characteristics.Using these criteria, development was divided into five phases: (1) condensation of coelomic epithelium; (2) secondary proliferation of coelomic epithelium; (3) finding of PAS-positive material within the fetal cortex; (4) decline and disappearance of the fetal cortex; and (5) establishment and stabilization of the definitive zonular patterns.Significant features occurring in this development were: (1) the origin of both permanent and fetal cortex from proliferation of coelomic epithelium; (2) the appearance of PAS-positive granules surrounding a homogenous mass in the fetal cortex and the zona reticularis during maturation and organization; and (3) the gradual establishment of definitive zones by proliferation of the permanent cortex, maturation of the fetal cortex, and growth of the medulla; with the adult structure of the adrenal gland achieved by the eleventh to fifteenth year without any apparent major involution or hemorrhage.
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  • 95
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 126 (1968), S. 349-363 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The mesothoracic leg discs of the blowfly, Sarcophaga bullata (Parker) were studied by electron microscopy during the third larval instar. As the peripodial membrane and separation form, the cells of the disc become elongated and perpendicularly oriented toward the separation. The cellular organelles do not undergo significant changes until the late third instar. At this time, there is a significant increase in the amount of granular endoplasmic reticulum and in the number of inclusions, particularly in those cells located more deeply in the disc. Nucleolar enlargement and an increase in the number of mitochondria are also observed at this time.The cells at the border of the disc form a columnar epithelium whose surface develops microvilli-like projections. These projections. These projections reach their maximum development towards the end of third instar.It is suggested that some of the observed changes may represent a phenotypic expression of secretion of cuticular material.
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  • 96
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Neurosecretory activity and fine structure of the supraesophageal and optic ganglia of Daphnia schødleri Sars were studied. The relative amount of paraldehyde fuchsin stainable material present was determined at “daylight” and at one and three hours following for animals maintained under photoperiods of 7.5, 10.5, 13.5, and 16.5 hours. More material was found after one hour in both ganglia and there was a tendency for more in the optic ganglion under 7.5- and 10.5-hour photoperiods.Sections made at two levels in the supraesophageal ganglion and one level in the optic ganglion were examined with an electron microscope. Posterior and anterior parts of the supraesophageal ganglion contain apparent nerve processes at the edge of the ganglion, parallel to the anterior-posterior axis; these have large granules. Neurons in both areas contain patches of presumed polysaccharide granules. In the posterior region are a dorsolateral and a ventrolateral glandular cell, presumably these occur on both sides of the brain. They have very well-developed endoplasmic reticulum and some large granules. The dorsal cell is usually at the tip of a glial attenuation.Concentric lamellar systems are located in dilated nerve processes of the first optic ganglion neuropile. Large whorls (about 3.5 μ) are composed of concentric lamellae. When lamellae do not form complete rings, they end in loops or in dilated tubules that are sometimes constricted as vesicles. Small whorls (1.5 μ) typically have lamellae joined into two or three thick layers. Mitochondria are frequently associated with the whorls. It is proposed that the whorls are active in synthesis, possibly neurohumor production.
    Additional Material: 11 Ill.
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  • 97
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In the spiroboloid millipeds the male gonopods develop from rudiments of both pairs of legs of the seventh body segment. They are first evident as “lumps” on the sternum of the seventh segment following the molt to instar 5; they replace the functional walking legs of the seventh segment of earlier instars. These “lumps” go through progressive morphological changes in each instar until they attain the adult form. It is evident that in the spirobolid millipeds the gonopods do not develop as a gradual modification of functional walking legs; rather they pass through a progressive growth and differentiation of their own.
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  • 98
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 124 (1968), S. 79-82 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A total of 1125 normal chick embryos, representing 25 each of the 45 stages of Hamburger and Hamilton, were removed, fixed in Bouin's solution, stored in 70% ethanol and weighed with a semi-micro analytical balance. Entire blastoderms of stages 1-8 were weighed, whereas only embryos-proper were weighed in stages 9-45. As a consequence, results constituted two groups, each of which showed a geometric rate of growth marked only by minor deviations which were related to specific events of normal growth and development.
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  • 99
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 124 (1968), S. 117-131 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Estimates of the number of ganglionic neurons of superior cervical sympathetic ganglia and the number of preganglionic axons in the trunks just caudal to these ganglia were obtained from a sample of primates that included: man, chimpanzee, baboon, stump-tailed macaque, rhesus monkey, and squirrel monkey. The number of ganglionic neurons ranged from 63,625 in a squirrel monkey ganglion to 1,041,652 neurons in a human ganglion. Estimates of the number of preganglionic fibers varied between 2,285 in a cervical sympathetic trunk of a squirrel monkey and 12,008 in a human specimen. The resulting ratios of preganglionic fibers to ganglionic neurons ranged from 1:28 in a squirrel monkey ganglion to 1:196 in a human ganglion.The data reported in this study reveal considerable variation in the ratio of pre- to post-ganglionic neurons, and as was noted in regard to the number of cells in the ganglion, the ratios of ganglionic to preganglionic neurons appear to increase as a function of body size. In contrast, the number of preganglionic fibers does not increase as strikingly with body size, but varies greatly in the same species. The resulting ratio between the two orders of neurons is, therefore, less predictable than the number of ganglionic neurons in any given ganglion.
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  • 100
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 124 (1968), S. 181-185 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The volumes of a sample of primate superior cervical sympathetic ganglia were measured and related to body weight and to the number of ganglionic neurons. Estimates of volumes of the ganglia varied between 1.956 mm3 in squirrel monkey and 173.530 mm3 in a human specimen. Average cell densities for the ganglia ranged from 4,455 cells/mm3 in a human ganglion to 32,528 cells/mm3 in a squirrel monkey ganglion. Mean cell territories varied from 0.0000307 mm3 in a squirrel monkey ganglion to 0.0002245 mm3 in a human ganglion.Analysis of the data reveals striking trends of correlation between body size, volume of ganglia, and average cell territories. Since similar correlations have been described for other types of neuronal cell aggregates, it is suggested that for any given nucleus, ganglion or cortical area, the neuronal packing density varies as a function of body size.
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