64 
the oöcyte spindle shall be. On the other hand, the arrangement of 
the oöcytes in the ovary might cause the spindle of those most pos- 
teriorly situated to become keimbahn-chromatin and of those next in 
order to transform into nuclei. According to this view the oöcytes 
depend upon chance for their final position in the ovary, and the 
fate of the spindle is decided by the environment of the oöcyte. 
The fate of the chromatin of the odcyte nucleus in Copidosoma 
reminds one very strongly of the ‘anello cromatico’ produced during 
the differentiation of the oöcytes and nurse cells in the ovary of 
Dytiscus marginalis (Grarpina, ’01; Depatsteux, ’09; and Ginruert, 
10). In this species the formation of nurse cells is accompanied by 
the production of a peculiar ring of chromatin. This ring arises from 
chromatin particles which GÜNTHERT claims may split off from the 
chromosomes. This cast out material is segregated in one cell during 
the four succeeding divisions resulting in one oöcyte provided with 
the chromatic ring and fifteen nurse cells which lack this substance. 
The germ cells which become eggs thus possess an extra body of 
chromatin, but this body is only part of that contained in the original 
nucleus and not all as in the oöcytes of Copidosoma. Boveri (’04) 
has compared the formation of the ‘anello cromatico’ as described 
by Grarpina with the chromatin-diminution process in Ascaris and 
I have pointed outh in another place (Heyer, 714) that the final 
result is the same in Dytiscus, Ascaris and Miastor where diminution 
processes also occur. In all three forms the germ cells possess a mass 
of chromatin not present in the somatic cells. We can now add one 
more example to this list, namely, Copidosoma. 
If Srivesrrir’s observations are correct we must consider the 
chromatin-body of Copidosoma as a keimbahn-determinant, since it 
enables us to trace the germ cells in the developing embryo. The 
evidence seems quite certain in the case of the monembryonic para- 
sitic Hymenoptera examined by SıLvEstkI; and it is, I believe, safe 
to conclude that a similar distribution of material from the keimbahn- 
chromatin occurs in the polyembryonic species. Although SıLvestkıi 
could not determine this he was able to state that only certain clea- 
vage cells were provided with this material, and the probability is 
very great that the history of the keimbahn-determinants is as definite 
in these as in the monembryonic species. Keimbahn-determinants of 
a chromatic nature have been described in only a few other animals. 
The possibility of the chromatic constitution of the pole-dise in chryso- 
