Amitosis in the Ovary of Protenor belfragei and a 
Study of the Chromatin Nucleolus. 
By 
Katharine Foot and E. C. Strobell. 
With plates XII— XX. 
In studying the ovaries of insects during their period of growtli it 
is impossible to avoid the conviction that the rapid increase in the number 
of nuclei which occurs at this time is not due alone to mitosis. If the 
development of the ovary is followed from the verv young larval stages 
when the whole ovary is not as large as a single terminal chamber of 
the ovary of a mature insect, one is impressed by the rare occurrence 
of mitoses and the inadequacy of these rare cases to account for the 
rapid increase in size of the ovary during this period. Our preparations 
of the ovaries of Euschistus variolarius made in 1807 showed what we 
believed to be a demonstration that in this form nuclei may arise ami- 
totically and develop into germinal vesicles, but we delayed Publishing 
these results until we could support them by a study of the ovaries in 
the larval stages of Protenor , the form which seems to present the 
strongest evidence for the theory of the continuity of the chromo- 
somes. In the summer of 1909, owing to the courtesy of our friend 
R. J. de la toure Bueno, we were able to obtain hundreds of mature 
Prolenor. Tliese mated and laid their eggs in the laboratory and we 
secured a large number of preparations of the testes, mature ovaries 
and embryonic divisions. We can support Morrill's (1910) observations 
that these eggs are laid “one at a time”. In many cases the eggs were 
deposited in the laboratory whilc the insects were under observation and 
whatever the position of the insect in the cage, the egg was siniplv 
dropped, never deposited on a leaf or any selected surface. Sometimes 
