SUMMARY OF CURRENT RESEARCHES 



RELATING TO 



ZOOLOGY AND BOTANY 



(principally inveetebrata and cryptog-amia), 



MICROSCOPY, Etc.* 



ZOOLOGY. 



VERTEBRATA. 



a. Embryolog-y. t 



Ovum of Cat4 — R. Vander Stricht has studied in particular the 

 problem of yolk-formation in the ovum of the cat. He traces the 

 gradual elaboration of the nutritive vitellus, which is represented (apart 

 from mitochondrial formations) by fatty globules. Some ova are rich 

 in the fatty deutoplasm, and others have little of it ; it seems likely that 

 these are destined to form females and males respectively. The matura- 

 tion, fertilization, and early stages of segmentation are described. 



Interstitial Tissue and Corpus Luteum of Ovary. § — N. Popoff 

 has studied the ovary of mole, bitch, and weasel. The medullary strands 

 in mole and bitch are due to a primary proliferation of the germina- 

 tive epithelium. Some canaliculi of the Wolffian body are transformed 

 in the mole into the rete ovarii. The internal segment of the mole's 

 ovary, developed from a fresh proliferation of the germinative epi- 

 thelium, is separated early from the external segment by a closed peri- 

 toneal capsule. The external segment is like a rudimentary testis. 

 This is suggested by the presence of strands analogous to the seminiferous 

 tubules of the embryo, of a rete, and of a fibrous capsule enveloped in a 

 peritoneal investment. This segment develops into the foetal interstitial 

 gland, characterized by medullary follicles and by interstitial cells. 



In the bitch the medullary strands retain their primitive character, 

 and numerous interstitial cells are differentiated within the connective 



* The Society are not intended to be denoted by the editorial "we," and they 

 do not hold themselves responsible for the views of the authors of the papers 

 noted, nor for any claim to novelty or otherwise made by them. The object of 

 this part of the Journal is to present a summary of the papers as actually 

 published, and to describe and illustrate Instruments, Apparatus, etc., which 

 are either new or have not been previously described in this country. 



t This section includes not only papers relating to Embryology properly so 

 called, but also those dealing with Evolution, Development, Reproduction, and 

 allied subjects. 



X Arch. Biol., xxvi. (1911) pp. 365-481 (6 pis. and 3 figs.). 



§ Arch. Biol., xxvi. (1911) pp. 483-556 (4 pis.). 



