SPERMATOGENESIS IN AMPHIBIA AND INSECTS ily 
parison. Possibly it is related to the micro-mitosome described 
by Gatenby (17) in Lepidoptera. Although we lack any defi- 
nite knowledge as to what this juxtanuclear body may be, atten- 
tion may nevertheless be called to the fact that it seems to be in 
no way related to the Golgi apparatus. The suggestion of 
Duesberg (20) (based on Voinov’s account), that these bodies 
represent Golgi elements, is, therefore, almost certainly incorrect. 
Finally, a word may be added concerning the mitochondria 
in the spermatid, especially in view of the wide divergence of 
Vejdovsky’s account (in a related genus, Diestrammena) from 
more recent work on other insects. In the first place, the 
development of the vacuoles on the periphery of the nebenkern 
(fig. 41), as described by Vejdovsky, is obviously the first step 
in the condensation of the chromophilic substance as already 
noted in the Hemiptera, etc. (Bowen, ’22). The chromophilic 
substance gradually condenses (fig. 42), though always in a some- 
what irregular way, and eventually disappears during the early 
stages in the elongation of the nebenkern. The exact nature of 
the ‘pattern’ which it forms is not clear in my preparations. 
The central substance, correctly described by Vejdovsky in the 
intermediate stages (see his figures 182, 183, and 184), seems not 
to arise from the chromophilic material as he believed, but to be 
differentiated de novo in the unstained area of the nebenkern, 
as I have described in the pentatomids and the grasshopper. 
The formation of vesicles on the mitochondrial tail sheaths 
is very striking in Ceuthophilus, and due to the general failure 
of the chromophobic substance to stain, it is not easy to follow 
their differentiation. Hence the error of Vejdovsky in describing 
them as fatty degeneration products of the central substance, and 
I can find no support whatever for his assertion that the mito- 
chondrial structures are entirely lost from the sperm. The vesi- 
cles in Ceuthophilus are, it is true, very confusing if one has not 
become familiar with them in more typical cases, for the inter- 
vening portions of the sheaths are often not demonstrated (fig. 
43), and one would be readily misled as to the actual meaning of 
the vesicles themselves. Somewhat later stages leave little 
doubt that the sheaths actually spin out along the tail filament 
