DAVIS: SPERMATOGENESIS. (es 
the spermatogonia, except that in place of the monosome (4) there is 
in the o6gonia a symmetrical pair. ‘This is in accord with the results 
of Wilson (:05"), who has shown that in those Hemiptera in which a 
monosome occurs in the male there is always one more chromosome 
in the odgonia. Miss Stevens (:06") has found the same to be true 
ot several Coleoptera. However, Sutton (:02) found only twenty-two 
chromosomes in the ovarian follicular cells of Brachystola, while in 
the spermatogonia there are twenty-three chromosomes. 
D. Chortophaga viridifasciata. 
The spermatogonia and apical cell are much as in Dissosteira. In 
a polar view of the equatorial-plate stage (Fig. EH, p. 72) there are 
also twenty-three chromosomes, of which twenty-two are autosomes, 
since they can be readily paired. The remaining chromosome (4) 
is a monosome. I have been unable to find any evidence of a pre- 
cocious conjugation of the spermatogonial chromosomes such as 
McClung (:05) found in this species. 
During the prophase of the last spermatogonial division the mono- 
some can be easily distinguished, since it has a much more ragged 
outline than the autosomes and lies in a more or less distinct vesicle. 
In the prophase of the other spermatogonial divisions it cannot be 
distinguished from the autosomes. 
E. Melanoplus femoratus. 
The testicular elements in Melanoplus are much smaller than in the 
preceding species, and, therefore, are not in general so favorable for 
investigation. ‘The primary spermatogonia are much like those of 
Dissosteira and partially surround the apical cell. On its proximal 
side this cell is surrounded by connective-tissue cells. ‘The apical 
cell (Plate 1, Fig. 3), like the other elements of the testis, is much 
smaller than in Dissosteira and contains no deeply staining granules 
in the cytoplasm, only the finely granular material which stains lightly 
with Bordeaux being present. 
The secondary spermatogonia show no essential difference from the 
same cells in Dissosteira, but the nuclei are even more irregular in 
shape. During the resting stage, when the chromatin has become 
most widely diffused through the nucleus, there is often present a 
deeply staining mass formed by an aggregation of chromatin granules; 
whether it has any connection with the monosome, I am unable to say. 
