AN EXTRA DYAD AND EXTRA TETRAD IN CAMNULA 417 
in the early germ cells. But one cannot be certain that degen- 
eration on a significant scale did not occur among the cells of the 
germ tract in some of the atypical animals. For in some of these 
individuals the ultimate number of follicles in the gonad could 
not be determined on account of the immature age of the speci- 
mens or the method of sectioning. 
Perhaps a word more should be said here about the degenera- 
tion of germ cells, for it may be asked if no degenerating cells 
were found in the testis of the atypical individuals. The answer 
is that they were, but they are no commoner in these individuals 
than in normal camnulan and in other orthopteran material. 
Every one who has studied such material is doubtless familiar with 
giant-cells containing multiple complexes and first spermatocyte 
cells in which all the chromosmes have failed to synapse. Such 
cells are frequently observed. They seem to be the source of 
the degeneration. I have been able to find no connection be- 
tween the degenerating cells and the phenomena we have been 
discussing. Follicles containing extra elements are as frequently 
free from all traces of degeneration as normal follicles. 
The diploid numbers in both individuals 950 and 2525 are 
twenty-three, twenty-four, and twenty-five. If we assume that 
each of these animals inherited a single unpaired supernumerary 
from one parent, the above three counts can be derived by one 
abnormal division of the extra element. <A precocious or delayed 
division in a prefollicular but postprimordial germ cell, with the 
two halves of the extra element passing to the same pole, would 
explain these variations. For one of the daughter cells from this 
mitosis and its descendants would be without any extra chromo- 
some, the other with its progeny would have a homologous pair 
of supernumeraries, while the remainder of the germ cells of this 
generation and their descendants would retain the inherited un- 
paired supernumerary. If this is the true explanation, the 24- 
chromosome class of cysts and follicles should be much larger 
than either of the other two. In individual 950 there are recorded 
three follicles of the twenty-three-chromosome class, six of the 
twenty-four-chromosome class, and six of the twenty-five class. 
In individual 2525 eleven follicles in the twenty-four-chromosome 
