absolutely clearly shows that the beginning of life 

 must be sought in the formation of the ovum in the 

 ovary, and the beginning of its development in 

 fertilization, namely in the influence of semen on 

 the yolk. And, of course, the essence of the powers 

 which condition all phenomena of nature remains 

 unknown. If all this can reduce the different 

 phenomena to one cause, this will make a great step 

 toward the goal we have established, (pp. 94 - 95) 



During the last four years, aspiration to a solution 

 of the aforementioned general questions was my 

 dearest hope. Devoting myself year after year to 

 the study of the formation, development, and 

 functions of cells, I have stuck to the idea that 

 elucidation of the ideas of development and activity 

 of the cells is the only way to select from the 

 labyrinth of recent presentations about the organic 

 world. The explanation of the causes of the vital 

 activity in the cells leads to a clear presentation 

 about life in general and about causes directing it 

 throughout the organic world, (p. 95) 



The following work of Warnek represents the first part 

 of investigations of his planned program; it is concerned 

 with ovum structure and processes of its division in the 

 gastropodan molluscs. 



Warnek began with the description of the form of oviposi- 

 tion of the different fresh-water snails; he detailed the 

 periods of oviposition in the region of Petersburg and the 

 structure of gelatinous mass surrounding the ovum. Later he 

 described the structure of the laid ova, especially in the 

 species used in this work: Lymnaeus stagnalis and the slug 

 Limax agrestis . Transferring to the principal part of the 

 work, throwing light on the study of division, Warnek paused 

 at the characteristics of the yolk granules filling the 

 fertilized ovum. Among these granules Warnek saw a light 

 spot which was not delimited from the yolk membrane and was 

 always situated in the center of the ovum. All the process 

 of division of the ova of the molluscs which he studied Warnek 

 divided into stages, described in succession. 



545 



