Q4 JOSE F. NONIDEZ 
The presence of massive prochromosomes is not of general 
occurrence among the Coleoptera. While it has been possible 
to find in Blaps hundreds of cysts in such a condition, it is evident 
that they are lacking altogether in other species. Miss Stevens 
(06, 709), who studied more than forty species of beetles, found 
them in but two species—Photinus pennsylvanicus and Limoneus 
griseus. She maintained that they are traceable directly to the 
chromosomes of the anaphase; indeed, they are but those chromo- 
somes which have retained their massive condition for some time. 
Arnold (’08) has described similar bodies in the early spermato- 
cyte of Hydrophilus piceus, and states that each of them repre- 
sents a somatic chromosome, although he gives no definite proof 
of this assertion. According to the descriptions of this author, 
there is not a confused stage between the last anaphase and the 
prochromosomes. 
Owing to the presence of such a confused stage in Blaps, we 
face here a serious difficulty in assuming that the prochromosomes 
are the representatives of the chromosomes of the spermatogonia. 
If there have been sharp criticism of this view when they 
arise directly from such chromosomes, still more skepticism will 
arise when considering that their individuality is apparently lost 
in a coarse network. We have, however, strong reasons favoring 
the former view, since the number of prochromosomes agrees 
with the diploid number and the large chromosomes can be rec- 
ognized as separated individuals during this stage. I wish, how- 
ever, to emphasize a point which stands out clearly in studying 
the chromosomes of Blaps. This is the remarkable plasticity of 
the chromatin which leads to surprising changes of shape, if not 
of volume, in the individual chromosomes. This could hardly 
be due to the effect of the reagents, since it appears in material 
preserved by different methods. As a result, it is very difficult 
to establish constant individual differences among the 
euchromosomes. 
The way in which the prochromosomes arise in Blaps suggests 
a profound reorganization of the chromatin within the prochromo- 
some, a process which might account for the considerable dura- 
tion of this stage. It is interesting to note that no threads, such 
