VOL. IV.] Recent LiteraUire. 109 



zoid are cytoplasmic, while the whole of the large posterior coils 

 is nuclear. The vesicle always attached to these is supposed to 

 be homologous with the posterior part of the body of the sperma- 

 tozoid of Chara, or the granular hinder part of the body of a 

 zoospore. 



While he was unable to demonstrate it, he considers it 

 extremely probable that the kinoplasm of the forward part of the 

 spermatozoid contains the centrosomes which are thus transferred 

 to the Qgg. 



In regard to the part which each element plays in the act of 

 fertilization, Strasburger comes to the conclusion that, as Weis- 

 mann believes, the nuclei are the direct agents of hereditary trans- 

 mission. As to the centrospheres and kinoplasm, the former are 

 supposed by our author to represent " the kinetic centres from 

 which the impulses lor nuclear division, and to a certain extent 

 for cell-division, proceed." The kinoplasm " we consider as the 

 conducting substance for the impulses that radiate from nucleus 

 and centrospheres, and represents the specific motile element in 

 the protoplasm." With each cell-division this kinoplasm is 

 supposed also to divide. 



The name proposed by Sachs, " Bnergid," is adopted for that 

 unit composed of nucleus, centrospheres, and kinoplasm. 



He is inclined to give up the view that in the resting nucleus 

 the segments are separated, and to adopt his earlier view that 

 they anastomose so as to form a net-work with no free ends. As 

 an argument against the autonomy of the segments in the resting 

 nucleus, the sudden change in their number which sometimes 

 occurs is cited. 



The conclusion finally reached is that the essence of fertiliza- 

 tion consists of the introduction into the " entwicklungslahig " 

 Q^g of the active " euergid " through which the rapid division of 

 the egg is inaugurated. 



Douglas H. Campbeli.. 



