GERM CELLS IN NEMATODES, SAGITTA 181 
the periphery at the vegetative pole (Fig. 54, B, 2). 
This body, which he called the ‘‘besondere Korper,”’ 
consists at first of ‘‘grobkérnigen” plasma which 
stains like chromatin but not so intensely; later it 
condenses into a round homogeneous body with a 
sharp contour. During the first five cleavage 
divisions the “‘besondere Kérper”’ is always confined 
to a single cell. At the completion of this fifth 
cleavage (32-cell stage), the blastomere containing 
this cytoplasmic inclusion is recognizable as the first 
“Urgeschlechtszelle” (Fig. 54, C, @) and its larger 
sister cell as the first ‘“‘Urentodermzelle” (Fig. 54, 
C, FE). The primordial germ cell is the last to divide 
during the sixth cleavage and the ‘“‘besondere KGr- 
per” does not, as before, pass entire into one of the 
daughter cells, but breaks up into a number of pieces, 
part of which are included in each of the two daughter 
cells (Fig. 54, D, X). One of these daughter cells 
apparently acquires more of the “besondere Kérper”’ 
than the other. This division appears to Elpatiew- 
sky to be differential, separating the primordial 
odgonium from the primordial spermatogonium, the 
latter being the cell which receives the larger portion 
of the “‘besondere Koérper” and which during the 
next (seventh) division is slightly delayed (Fig. 54, 
F). Subsequent to the seventh cleavage the remains 
of the “‘besondere Kérper’’ become pale and grad- 
ually disappear, apparently dissolving, and in the 
four germ cells resulting from the next division only 
occasionally can stained granules from this body be 
distinguished. 
