No. 535] GERM-CELL DETERMINANTS 



tains the "besondere korper" is the primordial germ 

 cell (Fig. 3, B, G). The first division of this primordial 

 germ cell (Fig. 3, C) results in two daughter cells, one of 

 which obtains a larger portion of the "besondere kor- 

 per" (X) than the other (Fig. 3,D). This is interpreted 

 as the differential division, the cell which possesses the 

 larger amount of the divided "besondere korper" giv- 

 ing rise to the male germ cells, the other to the female 

 germ cells in the hermaphroditic adult. The "beson- 

 dere korper" now gradually becomes paler and finally 

 disappears. Buchner ('10) and Stevens ('10) have con- 

 firmed Elpatiewsky's observations. The origin of the 

 "besondere korper" was not determined. 



These investigations show the germ cells of Sagitta to 

 be similar to those of Ascaris and Cyclops in that they 

 contain a darkly staining material not present in the 

 somatic cells. 



In Oophthora and other parasitic hymenoptera, Syl- 

 vestri ('09) finds that the nucleolus of the germinal 

 vesicle passes to the posterior end of the egg during 

 maturation ( Fig. 4, A ) . Here it remains until the cleav- 

 age nuclei reach the periphery (Fig. 4, B). The cells 

 which then come under the influence of the nucleolus be- 



