STUDIES ON GERM CELLS PAT 
but it is safe to assume that a further condensation occurs result- 
ing in an oval, homogeneous mass as in Copidosoma (fig. 65). 
The secondary nuclei When a stage about like that shown in 
figure 75 is reached, there appears within the cytoplasm of the 
anterior one-half of the oocyte a great number of spherical 
bodies which are arranged as in figure 75, and which resemble 
small nuclei. Figure 76 is an enlarged drawing of the anterior 
end of the section shown in figure 75. The secondary nuclei 
vary considerably in size. The substance within them stains 
like chromatin and is in the form of one or several small masses 
from which a few strands of chromatin granules radiate toward 
the membrane. These secondary nucleoli are present for only 
a brief period, having all disappeared by the time the chromo- 
somes are formed (fig. 77). Their origin and function are prob- 
lematical, but it seems hardly possible that they can arise from 
the germinal vesicle by budding, and hence we are forced to the 
same conclusions already stated in the case of Camponotus (p. 
SAE 
The germ-line-determinants. The fully grown oocytes of 
Apanteles contain the most conspicuous germ-line-determinants 
yet described (fig. A). Although its history during embryonic 
development is not known, the probability that it plays an 
important role in the formation of the primordial germ cells is 
so great that it seems safe to include it among the bodies to 
which the term keimbahn or germ-line-determinant has been 
applied. 
The first indication of this body occurs in a half-grown oocyte 
(fig. 73). Here a triangular area at the extreme posterior end 
may be distinguished from the rest of the egg by a slightly greater 
. staining capacity (somewhat exaggerated in fig. 73). This 
affinity for basic stains increases as the oocytes grow older, and 
a network appears (fig. 74) which very much resembles the 
‘netzapparat’ described by many writers both in germ cells and 
somatic cells (Duesberg ’11). In succeeding stages this network 
condenses into a solid mass (fig. 75), but cavities soon appear 
again (figs. 77, 80), and the threads become thinner (fig. 81). 
Finally a condition is reached (fig. 82) in which the threads break 
+ 
JOURNAL OF MORPHOLOGY, VOL. 26, NO. 3 
