摘要:

AbstractSensory hairs from antennulae and antennae of the two speciesOrchestia platensisKrøyer andTalorchestia deshayesiiAudouin were studied by means of light microscopy and scanning and transmission electron microscopy. The complicated cuticular structures of the hair wall are described and figured. The central hair cavity opens in a rather wide terminal pore. Dendritic cilia from sensory neurons with perikarya inside the antennae run the whole length of the hair and terminate in the pore opening. The distal parts of the cilia contain osmiophilic material. It is concluded on morphological grounds that the hairs are chemosensory organs

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1973.tb00451.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractUsing the Falck‐Hillarp method for demonstration of biogenic amines, the presence of indole alkylamine (possibly 5‐hydroxytryptamine) containing enterochromaffin cells in strongly ciliated areas of the lancelet intestine was confirmed. An electron microscopic investigation of these areas, i.e. the “lateral ciliated tract” and the “dorsal ciliated tract”, revealed two cell types. 1. Mucous cells, equipped with tall cilia and giant rootlets, constitute the dominating type. 2. Enterochromaffin cells, containing numerous electron dense granules, are sparsely scattered among the mucous cells. The intestinal indole alkylamine is believed to be involved in the regulation of cilia

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1973.tb00452.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractThe spermatozoon and some spermatid stages ofSiboglinum(Pogonophora) have been examined by light and electron microscopy. In the spermatozoon a helical acrosome, a helical nucleus and a “body” with axonema follow each other in normal sequence. Head and tail are joined by a very short neck region containing two modified centrioles. The posterior portion of the nucleus is surrounded by a mitochondrial sheath consisting of three tightly wound mitochondrial helices. In the main portion of the tail the 9+2 unit is sorrounded by a granular sheath of dense material. In the neck region a centriole adjunct develops into a dense substance containing about nine rods.At an early stage, when the centriolar apparatus and flagellum become associated with the nucleus, three large mitochondria with fairly regular cristae are seen at the base of the nucleus. A well developed Golgi apparatus is present in early stages. Rows of microtubules are observed encircling the spermatid nucleus.Compared with the primitive type of spermatozoon the pogonophore sperm shows elongated and specialized nucleus, acrosome and mitochondria. It is concluded that the ancestral form must have had a fairly primitive spermatozoon and that evolution has proceeded towards a modified sperm with complicated spiral structure in connection with the evolution of a modified biology of fertilization,viz.specialized spermatophores. It is not known how the spermatophore discharges the spermatozoa nor how the spermatozoa find their way to the eggs. Two kinds of sperms are produced in the gonads of Siboglinum. The atypical sperm is smaller than the typical

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1973.tb00453.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractA majority of the males of the brackish water shrimp,Macrobrachium idae, show a hypertrophy in the length of the second cheliped, the length and spinuosity of the appendix masculina and the width of the vas deferens, during the breeding season. Statistical analyses of the measurements of these characters show that this hypertrophy has only very little correlation to the size of the individual, and that the above sex characters have marked variation in a population having the same body length. The hypertrophy of these structures is more linked with the extent of development of the androgenic gland. Also, in such individuals, the androgenic gland shows signs of increased secretory activity as evidenced by increase in size of the cells, vacuolisation of cytoplasm and presence of degenerative areas. It is suggested that there is a direct relation between the secretory activity of the androgenic gland and the hypertrophy of these structures i.e. there is a “cause and effect” relation between the androgenic gland and the primary and secondary sex charact

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1973.tb00454.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractA light and electron microscopic re‐investigation of the pancreatic islet organ of the hagfish,Myxine glutinosa, has confirmed earlier observations that agranular and granular β‐cells are the predominant cell types. However, in addition a rare second granular parenchymal cell was observed in which the granules are spherical in shape with a mean diameter of 213 nm, contrasting with the predominantly ellipsoid granules which characterise the β‐cell. At present, this allegedly second granular parenchymal cell cannot be unequivocally equated with a named islet cell type and its nature remains somewhat prob

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1973.tb00455.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractThe effects of eye ablation in the morphogenesis of the trout skull (Salmo irideus Gib.)Removal of one or both eyes in rainbow trout (from 8 days before hatching to 6 days after) causes some malformations of development of chondrocranium and skull bones. The observations prove that they have a mechanical origin: they are due to a modification of the forces existing in the orbit region during the morphogenesis. Height of orbit is reduced bytaenia marginalissliding down, and length of orbit is reduced bylamina orbitonasalismoving backwards. The bone reproduces exactly cartilage deformations.RésuméDes ablations unilatérales et bilatérales du globe oculaire sont pratiquées sur des alevins de Truite à des stades variant de 8 jours avant à 6 jours après l'éclosion. A la suite de ces opérations, il apparaît que les malformations obtenues au niveau du chondrocrâne comme du crâne osseux sont d'origine mécanique et liées à des modifications des forces qui s'exercent au cours de la morphogenèse dans la région orbitaire. l'orbite est réduite dorsoventralement par l'abaissement de lataenia marginaliset dans son diamètre antéro‐postérieur par le recul de la lame orbitonasale. l'os suit fidèlement les d

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1973.tb00456.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractAction of prolactin in intact and hypophysectomized eels. IX Effect on N‐acetyl‐neuraminic acid (ANAN) content of the skin, in sea waterIntact male silver eels were gradually transferred from fresh water to sea water. The ANAN content of the skin is significantly reduced after 50 days in sea water. Ovine prolactin injected for 10 days is without effect on skin mucus.Eels were hypophysectomized the day before their transfer; after 20, 30 and 50 days in salt water, ANAN content is progressively reduced; prolactin injection starting just after hypophysectomy has no effect after 20 days, prevents the ANAN decrease after 30 days and significantly increases skin ANAN after 50 days. These effects are compared with those obtained after similar treatments in fresh water: in both media, mucus production is stimulated after prolactin treatment in hypophysectomized eels, but is not increased in intact animals. Simultaneous plasma sodium changes are discussed in the light of recent data on eel osmoregulation.RésuméChez l'Anguille intacte transférée graduellement en eau de mer, la teneur en ANAN de la peau subit une chute lente, significative au 50e jour. l'injection de prolactine pendant 10 jours n'a pas d'effet net.l'hypophysectomie pratiquée la veille du transfert en eau de mer provoque une diminution significative de la concentration en ANAN, 20, 30 et 50 j après l'opération. La prolactine ovine, injectée aussitôt après l'ablation, reste sans effet apparent après 20 j, puis normalise (30 j) et accroît nettement (50 j) le taux de l'ANAN cutané, reflet de la quantité de mucus. Ces réponses sont comparées à celles obtenues en eau douce, ainsi qu'aux variations de la natrémie dans ces deux milieux et discutées à la lumière de données récentes sur l'os

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1973.tb00457.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

E. G. Gray: The Synapse. Oxford Biology Readers (Ed. J. J. Head and O. E. Lowenstein) No. 35. Oxford University Press, London 1973. 16 pp., 18 figs. 20 p.W. Hanke: Vergleichende Wirkstoffphysiologie der Tiere. VEB Gustav Fischer Verlag, Jena 1973. 179 S., 50 Abb. 19,50 M.A. Strenger: Sphaerechinus granularis — Violetter Seeigel. Grosses Zoologisches Praktikum (Herausg. R. Siewing) Band 18e. Gustav Fischer Verlag, Stuttgart 1973. 68 S. 31 Abb. DM 22.—.F. Winkelmann: Sympetrum vulgatum — Heidelibelle. Grosses Zoologisches Praktikum (Herausg. R. Siewing) Band 14d. Gustav Fischer Verlag, Stuttgart 1973. 100 S. 29 Abb. DM

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1973.tb00458.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY