128 GERM-CELL CYCLE IN ANIMALS 
between the daughter nuclei (Fig. 40, D). In 
either case, however, the spindle remains persist, 
forming a basic staining strand with enlarged ends 
connecting the two nuclei. Since at this time and 
in all later stages the two or more spermatogonia may 
be found surrounded by an envelope of epithelial 
cells, it seems certain that, as Wieman (19106) 
maintains, the spermatozoa in a single cyst are 
derived from a single spermatogonium. 
A cyst containing four spermatogonia is repre- 
sented in Fig. 40, H. Here again appear the strongly 
basic staining spindle remains connecting the nuclei. 
These black strands persist until the succeeding 
mitotic division occurs as Fig. 40, F, which was 
drawn from a section of a cyst containing eight 
spermatogonia, shows. Spindle remains are still 
evident in later stages, as in Fig. 40, G, which repre- 
sents a cyst containing thirty-two spermatogonia, but 
were not observed in cysts containing more than 
sixty-four cells. 
Many investigators have figured spermatogonial 
divisions which result in rosette-like groups of cells 
similar to that represented in Fig. 40, F. Ap- 
parently, however, the spindle remains, if present, did 
not possess such a strong affinity for basic stains. 
Furthermore, only those of my preparations that 
were fixed in Carnoy’s fluid and stained in iron 
heemotoxylin exhibited these black strands. Similar 
spindle remains have been observed in Dytiscus, 
especially by Giinthert (1910), and Carabus (Go- 
vaerts, 1913), during the differentiation of nurse 
