376 MITCHEL CARROLL 
INTRODUCTION 
A. Scope of the paper 
The investigation, of which this paper is a preliminary report, 
is one of a series based upon a large collection of orthopteran 
material brought together by Doctor McClung for the study of 
chromosome behavior. The present investigation deals with the 
chromosomes of the genus Camnula, and derives its chief value 
from its relation to the preceding studies of the series. It is not 
yet possible to report on the chromosomes of a representative 
series of the genus. But the work has disclosed two phenomena 
of special interest. These are: the conjugation during matura- 
tion of a homologous pair of extra chromosomes, or supernumer- 
aries, and clear-cut, indisputable instances of definite numerical 
variations within the individual, in germinal chromosome com- 
plexes in non-pathological tissue. This paper is confined mainly 
to a consideration of these unusual conditions. Since, however, 
the camnulan chromatoid body differs somewhat in its behavior 
from similar structures hitherto reported, a short account is 
given of this element. 
B. Material and acknowledgments 
The genus Camnula is a member of the subfamily Oedipodinae 
of the orthopteran family Acrididae. But one species, pellucida, 
is recognized by taxonomists. This species inhabits the North 
American continent from the Atlantic to the Pacific. In the 
higher mountains it is found southward to Pennsylvania, else- 
where in the East it is confined to New England and Canada. 
In California it occurs in the San Joaquin-Sacramento Valley, 
and thence northward to British Columbia. In the Rocky 
Mountain region it penetrates southward to New Mexico and 
Arizona, and in the interior plains to Nebraska and Illinois. 
The northern limits of its range are not known. 
The species, according to Mr. J. A. G. Rehn, of the Academy 
of Natural Sciences of Philadelphia, is very plastic and greatly 
influenced by its environment, in color, size, and less decidedly 
in certain details of its external anatomy. 
