96 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
An extended study of the chromosomes during the maturation 
period has convinced me that every spermatocyte possesses the same 
number of bivalent autosomes of each of the three types. This is not 
a statement which can be easily demonstrated, since only rarely can 
the structure of all the elements of any one cell be determined with 
certainty. Viewed at slightly different angles the appearance of a 
M. 
: b 7 c 
NN. 
Fies. Ma, Mb, Mc. Successive sections of spermatocyte of Dissosteira caro- 
lina during the early anaphase of the first division. All the chromosomes 
are shown, the monosome being at the right in Fig. Mc. xX 966. 
Fig. N.— Polar view, metaphase of first maturation division of Dissosteira 
carolina. X 966. 
Fic. NN.— Polar view, metaphase of first maturation division of Stenobothrus 
curtipennis. X 966. 
chromosome may vary greatly, and at certain angles a given chromo- 
some may be indistinguishable from one of a different type. Polar 
views of the equatorial plate are most favorable for identifying the 
different forms, but even in such cases it is often impossible to be sure » 
of the structure of all the elements. However, in the most favorable 
2. a eee ee eg -) 
