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SUMMAEY 



OP CUEEENT KESEARCHES EELATINQ TO 



ZOOLOGY AND BOTANY 



{principally Invertehrata and Cryptogamia), 



MICROSCOPY, &c., 



INCLUDING OEIGINAL COMMUNICATIONS FEOM FELLOWS AND OTHERS,' 



ZOOLOGY. 



A. GENEHAL, including Embryology and Histology 

 of the Vertebrata. 



Development of the Graafian Vesicles.f — M. 0. Cadiat comes to 

 the conclusion that in both viviparous and oviparous vertebrates the 

 nutrient yolk is not produced by the cells of the ovisac, but by a 

 thick homogeneous membrane which invests the yolk, and which is 

 analogous to the vitelline membrane of the Mammalia. He thus finds 

 himself in agreement with such observers as Gregenbaur and Waldeyer. 

 In the oviparous forms, the epithelium of the ovisac is reduced to a 

 single layer of cells. The author recommends the cat as a most 

 suitable animal for the study of the development of the ovoblasts. 



Development of Parrots-I — Dr. M. Braun has his third and fourth 

 contributions on this subject ; in the first he deals with the connections 

 between the dorsal medulla and the intestine in birds. He is now 

 convinced that there are three separate points at which this connec- 

 tion obtains. In the young embryos of ducks, in which there were 

 from six to eight protovertebrae, the first point of connection obtains in 

 front of the terminal ridge, and this one is very narrow. The floor of 

 the medullary tube is continued ventrally into a funnel-shaped passage 

 which opens behind the endoderm ; in older embryos nothing is to be 

 seen of this passage. The second communication is formed by the 

 endoderm becoming raised dorsal wards in the middle line, and finally 

 coming into connection with the medullary tube by means of a relatively 

 wide orifice. This too becomes closed, and as the tail appears, a 



* The Society are not to be considered as responsible for the views of the 

 authors of the papers referred to, nor for the manner in which those views 

 may be expressed, the main object of this part of the Joiirnal being to present a 

 summary of the papers as actually published, so as to provide the Fellows with 

 a guide to the additions made fi'om time to time to the Library. Objections and 

 corrections should therefore, for the most part, be addressed to the authors. 

 (The Society are not intended to be denoted by the editorial " we") 



t Journ. Anat. et Phjsiol. (Robin), xvii. (1881) pp. 45-60 (3 pis.). 



$ Verh. Physikal.-med. Gesell. Wurzburg, xv. (1881) pp. 120-3, 173-5. 



