fourth stage. The total number of yolk globules grows to 

 twenty- four. 



SUBSEQUENT DIVISION. In each of the following 

 stages four yolk globules are formed. As an example the 

 ninth stage can be employed. In the given drawing (Figure 39, 

 50) the dividing ovum is pressed, so it is possible to see 

 a great number of globules of division. In the middle the 

 yolk globules of the fourth stage are situated. To these 

 last the oldest and large globules of the fourth stage are 

 adjoined, moving far aside from each other by pressure. 

 To the left of the globules of the third stage the globules 

 of the fifth stage are present, obliquely from which the 

 youngest globules of the ninth stage are twisted; they are 

 situated in the spaces between the globules of the fifth 

 and seventh stages. The globules of the seventh stage 

 originate also from the globules of the third stage and 

 are situated to the right of the last globules. Finally 

 between the yolk globules of the fifth, seventh and fourth 

 stages the globules of the eighth stage are present, arising 

 as a result of a second division of the globules of the 

 fourth stage. 



Further Warnek carried out an analogical analysis of 

 the fifteenth stage and established the origin of all globules 

 present at this moment of division. 



It is instructive to compare the genealogy of blastomeres, 

 established by Warnek, in gastropodan molluscs with recent 

 data. This comparison shows the complete agreement of Warnek 's 

 results with recent data, as seen from the table. In it the 

 designations applied by Warnek and the presently applied 

 literal numerical designations are given. 



The same comparison is given in Figure 41, where the 

 contours of drawings 40, 45, 47 and 50 of Warnek are repeated 

 and the data of the recent designations of blastomeres and 

 their designations by Warnek are compared. 



There is no doubt that Warnek completely and distinctly 

 chose to follow the fate of the separated blastomeres ("yolk 

 globules") and the participation of their descendants in the 

 formation of organs of the developing animal. Selecting an 



555 



