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  • 1
    Electronic Resource
    Electronic Resource
    Reactions of lead tetraacetate with substituted azomethines (1973)
    s.l. : American Chemical Society
    Chemical reviews 73 (1973), S. 93-112 
    Details
    ISSN: 1520-6890
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/cr60282a001
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  • 2
    Electronic Resource
    Electronic Resource
    A Redescription of Rhyncheta cyclopum Zenker (Ciliatea, Suctorida) (1972)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 19 (1972), S. 0 
    Details
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Rhyncheta cyclopum Zenker (Ciliatea, Suctorida) is described from Cyclops albidus and C. viridis occurring in small lakes in Cheshire. The adults have elongated or irregularly spherical bodies which are rounded apically and flattened basally. There is usually a single primary tentacle which is variable in position, length, and activity. Additional tentacles in various stages of growth and resorption may be present, and an account of these processes is given. The body is attached to the host by a short stalk. The barrel-shaped embryos are produced by a rapid or multiple endogenous budding. The presence of the stalk and supernumerary tentacles are described for the first time, and it is considered that these, together with other features, warrant a redescription of this species. The taxonomic relationship of R. cyclopum to other species of Rhyncheta is considered and a probable connection of the tentacle form in this suctorian with its possible food source is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1972.tb03537.x
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  • 3
    Electronic Resource
    Electronic Resource
    The development and structure of the zoospore vesicle in Bulbochaete hiloensis (1970)
    Springer
    Archives of microbiology 72 (1970), S. 223-237 
    Details
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary 1. Zoospore mother cells in Bulbochaete are shown to be surrounded by a structure interposed between the plasmalemma and the cell wall which is interpreted as the precursor of the vesicle which temporarily surrounds the zoospore on its release. 2. As this vesicle precursor matures it thickens apically to form a ring consisting of a core and two layers. These two layers envelope the young zoospore as its vesicle. Later a space, referred to as the sub-ring, develops within the middle layer of the ring. 3. Histochemical tests indicate that the vesicle precursor and ring are highly proteinaceous with a small carbohydrate component. 4. Dehiscence is apical and thought to be assisted by the apical ring. Upon release of the zoospore, its vesicle is essentially composed of the inner layer of its precursor.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00412174
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  • 4
    Electronic Resource
    Electronic Resource
    Reproduction in Bulbochaete hiloensis (Nordst.) Tiffany (1972)
    Springer
    Archives of microbiology 86 (1972), S. 265-280 
    Details
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary 1. The ellipsoid to subspherical zoospore of Bulbochaete hiloensis (Nordst.) Tiffany consists of a green body surmounted by a dome-shaped colourless head, around the base of which is a ring of flagella. 2. The body cytoplasm is characterized by a reticulated chloroplast which contains stacked thylakoids; incipient, developing and mature pyrenoids; and microtubules. The remaining cytoplasm contains active ER-Golgi complexes, coated vesicles, dense bodies, cored bodies, a mitochondrial nest, large central nucleus and lipid-like bodies, adjacent to the large vacuoles. 3. The colourless head, packed with mitochondria, has an extensive ER-Golgi system and a mass of vesicles thought to contain mucopolysaccharides. 4. The flagellar apparatus contains approximately forty regularly-spaced basal bodies situated below a banded fibrous ring. Between the basal bodies are located striated ascending roots, microtubular descending roots and supporting structures. 5. Zoospores are positively phototactic and it is suggested that motility is directed either through differential flagellar activity or by an internal steering mechanism affected by reorientation of the flagellar apparatus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00424984
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  • 5
    Electronic Resource
    Electronic Resource
    Reproduction in Bulbochaete hiloensis (Nordst.) Tiffany (1973)
    Springer
    Archives of microbiology 90 (1973), S. 343-364 
    Details
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary 1. Sexual reproduction in Bulbochaete hiloensis (Nordst.) Tiffany is mediated by the production of dwarf males and oogonia. 2. Mature dwarf males have a stipe cell and a variable number of antheridia, each divided by a septum separating two spermatozoids. 3. Each spermatozoid consists of a head and body surmounted by a flagellar apparatus with a ring of six to nine flagella. 4. The spermatozoid body is characterized by a large nucleus with chromatin but without an apparent nucleolus, and a highly reduced chloroplast with stroma starch but no pyrenoids. 5. Each spermatozoid is surrounded by a fibrous vesicle and an electron dense layer which are thought to be functional in the sequential release of the spermatozoids from the antheridium. 6. A vegetative photosynthetic cell undergoes division to eventually give rise to an oogonium and primary and secondary suffultory cells. 7. The suffultory cells have highly vacuolate, degenerate cytoplasm with no chloroplast. 8. Within the oogonium, the nucleus becomes located near an extracytoplasmic, fibrogranular mass of mucosubstances laid down in the vicinity of a partial wall discontinuity. These mucosubstances are possibly functional in splitting the wall to form the fertilization pore. 9. The plug progressively disperses as the oogonial cytoplasm rounds off, receding from the cell wall in the apical and basal regions. 10. Following fertilization the oogonial contents refill the enclosing cell wall. The nucleus returns to the centre of the cell and the cytoplasm becomes dominated by numerous closely-packed, lipid-like bodies. Stages in the development of the seven-layered oospore wall are described.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00408929
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  • 6
    Electronic Resource
    Electronic Resource
    Ultrastructural investigations in the stigonemataceae (cyanophyta) (1972)
    Springer
    Archives of microbiology 82 (1972), S. 283-299 
    Details
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary 1. The general cytoplasmic features of Fischerella muscicola, Stigonema hormoides and cells of Stigonema mamillosum found as a phycobiont in the lichen Ephebe lanata are similar to those found in other cyanophyte cells. 2. In all instances the outer surface of the quadrilayered cell wall bears a series of ridges. The membrane-like outermost layer (L IV) also exhibits a number of evaginations thought to represent sites of extrusion of material from the cytoplasm through the wall into the enveloping fibrous mucilage. 3. Cross walls are formed by inward growth of the two inner layers of the lateral walls, the daughter cells subsequently moving apart through the inward intrusion of the two outer wall layers and a bulk of mucilage. 4. The daughter cells remain connected by a persistent central region of the original septum. This septum is penetrated by pores, although these do not pierce the underlying plasma membranes and no direct connection of the protoplasts is achieved. 5. An apical cell of S. hormoides was found to be capped by remnants of a cross wall, presumably by the disruption of a previously distal cell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00424933
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  • 7
    Electronic Resource
    Electronic Resource
    The electrophysiology of the retina ofPeriplaneta americana L. (1973)
    Springer
    Journal of comparative physiology 83 (1973), S. 263-278 
    Details
    ISSN: 1432-1351
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. Intracellularly recorded illumination potentials from retinula cells (probably the green sensitive cells) of the cockroachPeriplaneta show the typical tetraphasic responses to graded intensities of light. In the dark-adapted state, the plateau phase is relatively greater than in the light-adapted state, and, in general, the responses are larger. 2. Angles of acceptance in the light-adapted state are 2.4±0.9 ° SD for the horizontal plane and 2.3±0.6 ° SD for the vertical plane. Angles of acceptance were about three times larger for dark-adapted cells, being 6.7±1.8 ° SD in the horizontal plane and 6.9±1.3 ° SD in the vertical plane. 3. In each state, the visual fields are circularly symmetrical. 4. The pigment movements and the palisade which develops upon dark-adaptation (Butler, 1973b) are the only anatomical features which can account for this change in acuity. 5. The above changes are similar in all ommatidia. Combining these measurements with the map of interommatidial angles (Butler, 1973a) leads to the conclusion that movement perception is not constant in different parts of the eye, and that changes during adaptation have unequal effects on movement perception in different parts of the eye.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00693678
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  • 8
    Electronic Resource
    Electronic Resource
    The anatomy of the compound eye ofPeriplaneta americana L. (1973)
    Springer
    Journal of comparative physiology 83 (1973), S. 239-262 
    Details
    ISSN: 1432-1351
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. The fine structure of the retina was studied using light and electron microscopy. 2. The eye is of the typical fused-rhabdomere, eucone, apposition type, with no unusual features or specializations. 3. Each ommatidium consists of a distal dioptric apparatus with cornea and four cells forming the crystalline cone. Proximal to this is a retina composed of eight retinula cells. Each ommatidium is surrounded distally by two primary pigment cells and proximally by several accessory pigment cells. 4. All retinula cells are similar and contribute to the rhabdom. 5. In the light-adapted state, retinula cell screening pigment particles congregate around the rhabdom, contrasting with the dark-adapted state where a palisade separates the screening pigment from the rhabdom.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00693677
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  • 9
    Electronic Resource
    Electronic Resource
    The anatomy of the compound eye ofPeriplaneta americana L. (1973)
    Springer
    Journal of comparative physiology 83 (1973), S. 223-238 
    Details
    ISSN: 1432-1351
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. The large compound eyes ofPeriplaneta are covered with irregular rows of low relief facets (10μm high). 2. Measurement of interommatidial angles show large variations in these angles for both horizontal and vertical planes. Trends exist, however, with horizontal interommatidial angles increasing posteriorly from 1.9 ° to 10.0 °, and vertical field angles increasing posteriorly from 1.0 ° to 4.7 °. 3. The maximum composite field of view for each eye is 240 ° in the horizontal plane, and 198 ° in the vertical plane. This results in a dorsal overlap of 40 °, an anterior overlap of 65 ° and a posterior overlap of 56 °. Thus, the necessary anatomical arrangement is present for binocular vision. 4. The eyes ofPeriplaneta are a very dark, uniform colour, and apparently lack pseudopupils. An alternative explanation of the pseudopupil phenomenon to that of Yagi and Koyama (1963) is given and it is postulated that virtually all insects have them, although they may not be visible.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00693676
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  • 10
    Electronic Resource
    Electronic Resource
    The electrophysiology of the retina ofPeriplaneta americana L. (1973)
    Springer
    Journal of comparative physiology 83 (1973), S. 279-288 
    Details
    ISSN: 1432-1351
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. Retinula cells ofPeriplaneta in the same state of morphological adaptation differ among themselves in absolute sensitivity by up to 1 log unit (tenfold). 2. Morphologically dark-adapted retinula cells are, on average, ten times as sensitive as light-adapted cells to light on the optical axis. 3. All retinula cells are about 5 times as sensitive to plane polarized light in the plane of its optimum effectiveness as in the orthogonal plane. 4. Retinula cells fall into two groups with optimum plane of polarization 90 ° apart, corresponding with the 2 planes of rhabdomeric microvilli.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00693679
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