442 
J. BRONTti GATENBY. 
body, and the latter never bears the same relationship in later 
stages to the nucleus as the acroblastic body. In Orgyia 
antiqua the acroblasts seem to be vesiculiform, but as my 
material is fixed in Meves* fluid I cannot be quite sure. In 
PI. 24, figs. 24 and 27, these bodies are shown, but the trace 
of acetic acid used seems to have abnormally affected them. 
They are less visible than after Champy or Flemming without 
acetic fixation. In Spilosoma the cell was too small for me to 
make sure of the presence of the acroblasts in the growth 
period, though the mitochondria could be seen. 
* 
The Mitochondria and Other Bodies in the 
Female. 
In every way the cytoplasmic bodies in the oogonia and 
younger oocytes resemble the same structures in the male; 
this is a point which has hitherto escaped notice in the Lepi- 
doptera, and it is one of significance. It is not till the growth 
period has begun that the male cell becomes different from 
the female. In the former I have found micromitosome, 
spindle bridge, and mitochondrial cloud, and these bodies are 
all present in the female, though they may be slightly 
different in some ways. In the oogonium the mitochondria 
are grouped just as in the spermatogonium, and the same 
applies to the behaviour of these bodies during the oogonial 
divisions. After divisions have ended, the prophases of tho 
heterotypic division begin, and the cell looks like that drawn 
in PI. 24, figs. 26 and 28. The spindle bridge at this period 
may be relatively enormous, as in the latter figure, and it is 
often surrounded by, or closely related to, the mitochondria 
in some way or other (PI. 24, fig. 26) ; these cases vary greatly. 
In PI. 24, figs. 25, 26, and 28, there is a body (M.) which i& 
almost certainly the micromitosome ; in both Smerinthus and 
Pygaera I am quite certain of its presence. If ovaries and 
testes are preserved and stained at the same time these bodies 
can readily be compared (see PI. 23, fig. 4, and PI. 24, fig. 25- 
both oocyte and spermatocyte being at contraction figure), 
The micromitosome of the female seems to stain less heavily 
