CYTOPLASMIC INCLUSIONS OP THE GERM-CELLS. 415 
are the mitochondria. They need no further mention at 
this juncture. 
It will now be clear that my account of the bodies in the 
cytoplasm of the spermatogonium differs from that of Meves 
in my denial of the presence and significance of an idiosome 
(archoplasmic zone) and in my account of the micromitosoine 
overlooked by the German cytologist. I would like to make 
it quite clear that if any small granules do possibly appear 
around the centrosome I am convinced that they have no 
connection with any other body in the spermatid, and that 
in this case Meves and I would differ in the significance 
we attach to such a zona. No other bodies can be seen with 
certainty in the cytoplasm of the spermatogonium. 
Almost all the work on the cytoplasmic bodies of the 
germ-cells of insects consists in the description of these 
bodies from the spermatid onwards, and it is the identification 
and interpretation of these bodies in the spermatid which 
have led to a great confusion. Meves has, as already stated, 
overlooked some cytoplasmic bodies, both Munson ( 6 ) and 
Platner are confused in their treatment of these structures, 
and some other authors also seem to have failed to distinguish 
centrosome from acrosome. The correct usage of the term 
“ nebenkern ” is doubtful. According to Paulmier (12) 
u nebenkern ” means a body formed from the spindle fibres 
and yolk granules. In the text-book on ‘ Cytology 3 Wilson 
(7) offers the following remarks : “ The foregoing account 
shows that our positive knowledge of the formation of the 
spermatozoon still rests on a somewhat slender basis. . . . 
All agree, further, that the middle piece is of archoplasmic 
origin, being derived, according to some authors, from a true 
attraction sphere (or centrosome) ; according to others, from 
a ‘ nebenkern 3 formed from the spindle fibres. The former 
account of its origin is certainly true in some cases. The 
latter cannot be accepted without reinvestigation, since it 
stands in contradiction to what is known of the middle piece 
in fertilisation, and is possibly due to a confusion between 
attraction sphere and f nebenkern. ’ Similar doubts exist 
