SUMMARY OF CURRENT RESEARCHES 



RELATING TO 



ZOOLOGY AND BOTANY 



(principally invertebrata and cryptogahia), 



MICROSCOPY, Etc.* 



ZOOLOGY. 



VERTEBRATA. 



a. Embryology. t 



Development of Rabbit's Embryo in Vitro. J — A. Brachet has 

 been able to secure for 24-48 hours the development of " explanted " 

 blastodermic vesicles of the rabbit (from the sixth or seventh day) in 

 plasmic media, formed from the rabbit's blood. They not only remained 

 in life : they exhibited progressive development. The noteworthy 

 result is that in the artificial plasmic medium the development was not 

 appreciably altered. Thus the placenta, whose formation might have 

 been supposed to require the direct action of the uterine mucosa, not 

 only made its appearance but had its foundations laid just as if the 

 blastodermic vesicle had remained in the mother. A blastodermic 

 vesicle with a didermic embryonic disk, but otherwise undifferentiated, 

 is explanted into a blood clot and submitted, therefore, to uniform 

 influences all over its surface, yet its development for the short term 

 of its survival is quite normal ; it forms an embryo, an ectoplacenta, 

 and a papuliferous zone. There are only slight differences in detail. 

 It follows from this important conclusion that the influence of the im- 

 mediate normal environment within the mother is not so rigorously 

 indispensable as some have supposed. Plasma formed from the blood 

 of the male rabbit is just as suitable as that from the blood of the 

 female. The general conclusion is that the internal causes of organo- 

 genesis are of paramount importance. 



Artificial Parthenogenesis in Amphibians.§— E. Bataillon dis- 

 tinguishes between the activation of the egg and its karyocatalysis (an 



* 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. 



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

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

 allied subjects. J Arch. Biol., xxviii. (1913) pp. 449-503 (2 pis.). 



§ Ann. Sci. Nat. (Zool.) xvi. (1912) pp. 257-307. 



