138 GERM-CELL CYCLE IN ANIMALS 
regions of the insect ovary and, since Payne (1912) 
has shown that in Gelastocoris the cells that appar- 
ently multiply amitotically do not produce ova, it 
seems safe to conclude that in Protenor the ova are 
not descended from cells that divide amitotically. 
Amitotic division of germ cells followed by mitotic 
division has been described by Wieman (19100, 
1910c) in the ovaries and testes as well as in the nurse 
Fic. 43.— Stages in amitosis in spermatogonium of Leptinotarsa signa- 
ticollis. (From Wieman, 1910.) 
cells of a chrysomelid beetle, Leptinotarsa signatt- 
collis. Germ cells in both ovary and testis taken 
from full-grown larve were found in stages of divi- 
sion recognized by Wieman as amitotic (Fig. 43). 
It was difficult to demonstrate actual division of 
the cytoplasm, but that such a division really occurs 
was inferred because binucleated cells apparently 
gave rise to spermatocytes with single nuclei. Rapid 
cell division is assumed by Wieman to account for 
amitosis. This is brought about by fluctuations in 
the nutritive supply or, in the case of the testis, by 
the rapid proliferation of cells during the formation of 
cysts. 
