( 918 ) 

 RECORD 



OF CURRENT RESEARCHES RELATING TO 



INVERTEBEATA, CRYPTOGAMIA, MICROSCOPY, &c.* 



ZOOLOGY. 



A. GENERAL, including Embryology and Histology 

 of the Vertebrata. 



Impregnation of the Animal Ovum.f — Professor Schneider states 

 that the impregnating spennatozoa disappear, either by breaking up 

 into small pieces or by uniting to form nucleated spherules, which 

 gradually diminish and disappear. The observations on which this 

 statement is based were made on the eggs of Aulostomum, Nephelis, 

 Piscicola, and Mesostomum Ehrenhergii. In Aulostormim and Piscicola 

 there were hundreds, in Nephelis thousands, and in Mesostomum about 

 ten entering spermatozoa. The formation of the first amphiaster has 

 nothing to do either with their presence or their absence. 



In Aulostomum and Piscicola the author made the important obser- 

 vation that the spermatozoa pass into the unripe egg, and are there 

 broken up. This explains how it was that Robin took the ovaries of 

 Nephelis for oospermatophores. In this form the spermatozoa are 

 set radially, and maintain their movements for some time after their 

 entrance into the egg. 



Influence of Light on the Development of Animals. J — M. Yung 

 states, that from observations which he has been making at Naples, he 

 is able to confirm, with regard to marine forms, the results arrived at 

 by him in experiments on fresh-water forms. Eggs of Loligo vulgaris, 

 and Sepia officinalis, placed in vessels containing two litres of water, 

 and subjected to monochromatic lights of different shades, developed 

 at unequal rates, those which were under violet or blue had their de- 

 velopment accelerated, those under red or green retarded. Yellow 

 most resembles white light in its eff'ects. Such larval specimens of the 

 Ascidian, Ciona intestinalis, as fixed themselves to his violet glasses 

 grew more rapidly and gave rise to more vigorous individuals than 

 those which fixed themselves to the other vases. Contrary to his 

 earlier results, he finds that development, though retarded, is in fact 

 effected under the influence of red or green glasses. 



* 1^° It should be understood that the Society do not hold themselves respon- 

 sible for the views of the autliors of the papers, &c., referred to, nor for the manner 

 in which those views may be expressed, the object of the Kecord being to present 

 a summary of the papers as actually published. Objections and corrections should 

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



t ' Zool. Anzeig.,' iii. (1880) p. 426. 



X 'Comptes Rendus,' xci. (1880) p. 440. See also ' MT. Zool. Stat. Neapel,' 

 ii. (1880) pp. 233-7. 



