68 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
The cytoplasm outside the granular mass is abundant, but much 
clearer than that of the surrounding spermatogonia. 
The study of a large number of testes of different ages in this and 
other species has failed to show any other stages in these cells. ‘They 
always appear approximately the same except for the differences in 
the condition of the granular mass surrounding the nucleus. 
Lying outside and surrounding the primary spermatogonia are 
large numbers of connective-tissue cells (Plate 4, Fig. 67), which can 
be easily distinguished from the spermatogonia by their smaller size, 
the relatively small amount of cytoplasm, and the deeper staining 
qualities of the nucleus. When the primary spermatogonia divide, 
one of the daughter cells is usually forced out of the layer of cells sur- 
rounding the apical cell. This cell then becomes intimately asso- 
ciated with one or more of the connective-tissue cells, which form an 
investment around it. ‘This investment persists until the descend- 
ants of the cell are converted into spermatozoa. 
Sutton (:00, :02) maintained that in Brachystola the spermatogonia 
and the cyst cells have a common origin, and that in the earlier genera- 
tions they are indistinguishable. I believe that the cells which he 
at first (:00) took to be primary spermatogonia and later (:02) to be 
the first generation of secondary spermatogonia are all, in reality, 
connective-tissue cells. Sutton was unable to find any transitional 
stages connecting these cells with the later generations of spermato- 
gonia. In my own preparations of Dissosteira and other species of 
the Acrididae, the two types of cells are always easily distinguishable, 
and I have seen nothing to indicate a genetic connection. 
The investment of spermatogonia by cyst cells marks the transition 
from primary to secondary spermatogonia, the spermatogonium with 
the surrounding cyst cells forming the beginning of a spermatocyst. 
The secondary spermatogonia divide mitotically in rapidly succeeding 
divisions, the daughter cells remaining enclosed by the cyst wall. 
It is thus evident that all the cells in each cyst are the direct descend- 
ants of a single primary spermatogonium, which became surrounded 
by a connective-tissue investment. At the distal end of each follicle 
are always a number of cysts containing from one or two up to a large 
number of secondary: spermatogonia, according to their age. In 
striking @ontrast to the primary spermatogonia, where adjacent cells . 
are often in very different stages, all the cells of a cyst are usually in 
practically the same stage of development. 
Occasionally nuclei in the cyst wall can also be seen undergoing 
mitosis. 
