180 GERM-CELL CYCLE IN ANIMALS 
given Sagitta a new importance, since this writer has 
found within the fertilized egg a cytoplasmic inclu- 
sion which is intimately associated with the segre- 
gation of the germ cells. The presence of this inclu- 
sion has been confirmed by Buchner (1910a, 19106) 
x 
NZ 
SS 
ZS 
Fic. 54.— Sagitta. A. First appearance of the ‘‘besondere Kérper” 
(bK) in the egg. B. Egg with germ nuclei fusing. X = ‘‘ besondere 
Korper.” C. Thirty-two-cell stage; the primordial germ cell (G) 
contains the ‘‘ besondere Korper"’ (X). D. Two entoderm cells (EZ) 
and dividing primordial germ cell. HE. Two primordial germ cells 
showing unequal distribution of ‘‘ besondere Kérper”’ (X). F. Di- 
vision of first two primordial germ cells; one dividing more rapidly 
than the other. (From Elpatiewsky, 1909, 1910.) 
and Stevens (19105), and several ideas have been 
expressed regarding its origin, fate, and significance. 
Elpatiewsky (1909) found in Sagittta, at the time 
when the male and female nuclei were lying side by 
side in the middle of the egg, a body situated near 
