CHROMOSOMES OF TIGER BEETLES 449 
A study of the anaphase stage clearly shows that the diploid, 
and not haploid, number passes to each pole. It will be noted in 
figure 15 b that, even though the chromosomes have coalesced, 
the diploid number still persists. These observations corroborate 
those of Metz on the corresponding stages in the Diptera, but 
oppose the view of Lomen (’14) and Taylor (714). 
The position of spindle fiber attachment varies with the shape 
of the chromosomes. In case of the unequal armed V’s (pair A) 
and the hooks or J’s (pair B), the fibers are attached at the apex 
of the angle formed by the arms. In the open U’s the fibers 
also seem to arise from the median region. In the straight rod 
chromosomes the spindle attachment is terminal. 
C. Late spermatogonia 
The last spermatogonial cells and mitotic figures, as well as 
the entire cysts, are characteristically different from those of 
earlier stages. The cysts are much more pronounced, having 
large intervening non-cellular spaces; they are very large and 
contain many more cells than in the earlier stages. ‘The number 
of cells was counted in fifty typical cross-sections, and the aver- 
age for each was thirty-seven. Since each cyst continues through 
about eight 5u sections, the total number of cells in each cyst 
would approximate 250, allowing for those which might appear 
in two sections. However, the cells here are only 7 in diameter, 
as opposed to 11, in the former stages. 
The secondary spermatogonial mitotic figures are much 
smaller than the primary. This renders an analysis of the 
spindle content much more difficult, as the same number of 
chromosomes is crowded into a much smaller space. It was 
impossible to study the chromosomes except at metaphase, and 
even here the entire plate could not be analyzed. Figures 12 
and 13 represent the most favorable plates. Neither of these, 
even though they are clearer than revealed by the microscope, 
shows twenty-two chromosomes. There is no doubt, however, 
that the full number could be counted, were it possible to obtain 
sufficiently differentiated material. Further, the chromosomes 
of the late divisions differ in shape from those of the earlier. 
