514 
Max Morse 
Wilson and Montgomery in every point while Wilson hiniself 
reaffirmed his conclusious after a reexamination based on sections, 
smear preparations and living- material. Moreover, a plasmosome was 
recognized and takeu into account by Wilson and by Lepevre and 
Mc Gill in their countings. In the present material, as bas already 
been said, counts liave been made in Auerbach preparations, where 
the plasmosome stood out clearly as a red body amongst the green 
chromosomes. No chance for error, whatsoever, is given under such 
cireumstanees. 
Gutherz (’07) Claims to have seen in the oöcytes of Syromastes, 
a ehromosome-nucleolus such as he finds in the spermatocytes and 
on this ground he questions the occurrence of an odd chromosome. 
Moreover, he does not find such a body in any of the somatic cells 
undergoing mitosis. Doubtless the bivalent nature (Wilson ’09) of 
the "ac-cessory chromosome” of this species may have to be taken 
into consideration in such conclusions. 
Various writers have described, as the present writer has done, 
a close association of the odd chromosome and the plasmosome. 
Thus, Montgomery (*01) described such an association for many of 
the Hemiptera, Stevens ( : 05) for Stenopelmatus , Baumgartner (’04) 
for the cricket, Davis (’08) for Acrididae and Locustidae, while a 
similar association has been found in the idiochromosomes of Hemi- 
ptera by Wilson ( ; 05) and by Payne (’09) in many other species. 
In some forms, apparently, no plasmosome is present, as Berry 
(’06) has stated for Epeira and Stevens (’05) for Stenopelmatus. 
Paulmier (’99) figures the plasmosome as bearing no relation to the 
odd chromosome. 
The writer has described earlier in the paper, a close associa- 
tion, in Stylopyga orientalis , between the plasmosome of the several 
stages after the spermatogonia. Even in the spermatogonia, one 
chromosome appears to be embedded within a plasmosome, but it is 
impossible to determine whether this bod}’ is the odd chromosome 
or not. Similar conditions have been described by Payne (’09) for 
various Hemiptera, where the idiochromosomes of the spermatocyte 
growth period are collected together within the plasmosome. There 
seems therefore, from the evidence of this and other material, that 
there is some definite relation between the single conspicuous plas- 
mosome and the odd chromosome or idioehromosome of Hexapoda, 
although there is nothing to demonstrate its nature nor the function 
of the plasmosome. It may be that the idiochromosomes undergo 
