281 



SUMMARY OF CURRENT RESEARCHES 



RELATING TO 



ZOOLOGY AND BOTANY 



(principally invertebrata and cryptogamia), 



MICROSCOPY, Etc.* 



ZOOLOGY. 



VERTEBRATA. 



a. Embryology, t 



Foundations of Embryology.! — Bruno Bloch has made a scholarly- 

 contribution to the history of Embryology, in which he deals with the 

 " foundations," if they are worthy of that title. His chapters discuss 

 (1) the Hippocratic school, (2) Aristotle, (3) Galen, (4) from Galen to 

 the beginning of the sixteenth century, and (5) thence to Harvey. 



Interstitial Cells in Ovary of Rabbit.§ — Janet E. Lane-Claypon 

 has studied the origin and life-history of these elements. A large 

 number of germinal cells become imbedded in the subjacent mesoblast. 

 Of these the great majority undergo transformations up to a certain 

 stage. This stage having been reached, they may pass through the 

 necessary processes of ovogenesis, or they may become modified to form 

 either follicle cells or interstitial cells, this last process being the chief 

 fate of those near the periphery, whilst ovogenesis occurs in those more 

 centrally situated. 



The interstitial cells are thus potential ova, capable of becoming 

 ova should the appropriate stimulus be given. This stimulus is pro- 

 vided by pregnancy, during which the interstitial cells undergo en- 

 largement in size, exceeding that of a primordial ovum. About the 

 twenty-third day some of the interstitial cells become cut off near the 



* 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 pub- 

 lished, and to describe and illustrate Instruments, Apparatus, etc., which are 

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



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

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

 allied subjects. 



X Nova Acta Leopold-Carol. Acad. Halle, lxxxii. (1904) received 1906, pp. 217- 

 334. 



§ Proc. Roy. Soc, Series B, lxxvii., No. B514 (1905) pp. 32-57 (1 pi.). 



