ISSN:0373-4137    

DOI:10.1080/11250005709438240

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor

摘要:

The metabolism of tcstostcrone and estradiol 17β by larvae ofDufo vulgaris, Rana esculcnta, Triton cristatus, Xenopus laevishas been investigatedin vivo.

ISSN:0373-4137    

DOI:10.1080/11250005709438241

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor

摘要:

The Authors performed an hystochemical research for lipids and steroids on corpus luteum ofTorpedo marmorata(ovoviviparous species) andScylliorhinusca-nicula(viviparous species), whose morphological likeness with those of Amniota was long since recognized.

ISSN:0373-4137    

DOI:10.1080/11250005709438242

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor

ISSN:0373-4137    

DOI:10.1080/11250005709438243

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor

摘要:

The results of various crosses have shown that the colour patterns of the CopepodTisbe reticulataliving in the Lagoon of Venice is due to a series of at least three allelomorphs at the same locus, two of which dominant over a common recessive. The Same two allelomorphs do not exhibit dominance when occurring together; consequently this heterozygote is phenotypically detectable. There is some evidence that, under laboratory conditions, this heterozygote is more viable than both the respective homozygotes.

ISSN:0373-4137    

DOI:10.1080/11250005709438244

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor

摘要:

The mitotic activity in the germinal laycr of the hindbrain was studied in larvae of anouran and urodelan Amphibians. The mitotic activity does not cease till a month after metamorphosis; therefore the number of the nerve cells in the Amphihian hindhrain is determined late. The proliferation of the dorsal half (alar lamina) is consistently higer than that of the ventral half (basal lamina); this differential mitotic activity can be explained supposing that the morphogenesis and the growth of the neural tube are supported chiefly by the activity of the alar lamina. The differences in the mitotic activity of the germinal layer between anouran and urodelan Amphibians arc due to the regulative processes of the development of the examined species. The mitotic patterns of the alar lamina show in most respects contrasting features, which have been correlated with the different ecology of those Amphibians; i.e. the peak observed in the Anouran is related to the development of the nervous centers functionally connected with terrestrial life (cerebellum), on the contrary in the Urodelan it is related chiefly to the growth of the central nervous system.

ISSN:0373-4137    

DOI:10.1080/11250005709438245

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor

摘要:

The hermaphrodite Polychaet wormSulmacina incrustansCLAP., besides the sexual process of reproduction, may multiplicate by simple fission (budding). It has been ascertained that a direct relation exists between the number of thoracic segments of the specimen reproducing aseXually and the number of thoracic segments of the schizozooid originated by the former.

ISSN:0373-4137    

DOI:10.1080/11250005709438246

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor

摘要:

The comparative examination of the nuclei of the retinal nerve cells in some Vertebrates has shown that the size-ratio of the retinal nerve cells is different in the various Vertebrates. The beterochromatic network fills the nuclear sap in the Vertebrates whose retina becomes quickly differentiated (Anamniota), on the contrary the network sticks to the nuclear membrane and to the nucleolus (nucleolus-associated chromatin)in the Vertebrates whose retina gets slowly differentiated (Amniota); in the Amniota some heterochromatic structures remain between the nuclear membrane and nucleolus only in the ganglion cells, which develop early and quickly. These results support my previous suggestion that the developmental speed of the nerve cell affects the arrangement of its heterochromatic structures.

ISSN:0373-4137    

DOI:10.1080/11250005709438247

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor

ISSN:0373-4137    

DOI:10.1080/11250005709438248

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor

摘要:

Also inColpodaantigens are present; their presence is demonstrated by the characteristic «immobilization reaction» concerning the organisms of the same type as those injected in the rabbit. Making a comparison betweenColpodaandParameciumwc can see that the immobilization reaction is rather similar in both eases; the titre of the serum is lower inColpoda, and the separation of resistant animals is much more difficult. An absorption of antibodies has been observed in some cases. After having absorbed antibodies, the Ciliates can grow in serum. A relationship between the time of immobilization and the stage of the life cycle has been found. No relationship between the time of immobilization and the temperature at which the organisms have been cultivated. The serum fromC. cucul-lusdoesn't immobilizeC. maupasiandP. aureliavar. I. The action of the serum fromC. maupasiis not yet clear in the case ofC. cucullus;this serum doesn't immobilizeParamecium.

ISSN:0373-4137    

DOI:10.1080/11250005709438249

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor