530 ROBERT W. HEGNER 
ment of this body were found and they seem to indicate a con- 
dition similar to that described in Copidosoma and Apanteles. 
The earliest stage discovered (fig. 84) represents an asterless 
spindle bearing a number of pairs of chromosomes attached near 
their ends and drawn out so as to form a more or less parallel 
series. These pairs then condense, as shown in figures 85 and 
86, and finally produce the pear-shaped body mentioned above 
(fig. 83). Apparently the chromosomes become completely 
fused in forming this body, since a high magnification (fig. 87) 
reveals nothing more than a vacuolated mass of chromatin. The 
nucleus in Copidosoma never seems to undergo vacuolization, 
nor does the similar body described in Ageniaspis by Martin 
(14). 
No body was found near the posterior end of the oocytes of 
the oak-knot gall-fly such as occur in those of Copidosoma, 
Apanteles, and the blackberry-knot gall-fly next to be described. 
The maturation spindle and germ-line-determinants in_ the 
blackberry-knot gall-fly, Diastrophus nebulosus. The eggs of the 
blackberry-knot gall-fly (fig. 88) resemble in general shape and 
size those of the oak-knot gall-fly (fig. 83) and the nucleus is in 
a similar position. This nucleus forms a rather compact body, 
but not a homogeneous mass. The stage represented in figures 
89, 90 and 91 may be one of a series ending in the production 
of such a mass, but no other stages were found. Figures 89 and 
90 were drawn from longitudinal sections and show that the 
position of the oval nucleus may vary; figure 91 is from a trans- 
verse section. 
At the posterior end of the egg (fig. 88) is a more or less spheri- 
cal body to which we are justified, I believe, in applying the name, 
germ-line-determinant. This body stains black with hematoxy- 
lin and is filled with vacuoles (fig. 92). Weismann (’82) de- 
scribed a body near the posterior end of the eggs of Rhodites 
rosae which he called the ‘Furchungskern,’ but it is evident from 
his account and figures that this body is similar to the one I 
have just described and is not a cleavage nucleus. According 
to Weismann this body spreads out during cleavage and occupies 
