320 TAKU KOMAI 
clear space common to both. Next, in figure 45, the centrosome 
has already completed its transformation, while associating with 
its fellow and before being imbedded completely within the 
nucleus; such however, is apparently to be regarded as an 
abnormal case. Judging from what is represented by these two 
figures, but particularly by the latter, it is very evident that the. 
centrosome converted into rod-shape is to be identified as the 
proximal centrosome and not the distal as in the decapod sper- 
matozoon. 
Contrary to the proximal centrosome, the disal one (c. 2) 
undergoes virtually no change at all. It is placed usually in the 
center of the homogeneous part of the nucleus (figs. 47 and 51), 
but may not infrequently be quite eccentric in position in that 
part or may be situated just upon the boundary between that 
part and the perforatorium (figs. 49 and 50), or even within the 
latter (fig. 48). 
The nucleus further diminishes its size, whereas the entire 
cell enlarges and its wall thickens, until finally the’ mature 
state is attained (fig. 51). 
By the stage shown in figure 39 the mitochondrial body forms - 
a cupule-shaped mass lying over the nucleus; when the nucleus 
comes in contact with the cell walls it assumes a ring shape and 
takes the position between the nucleus and the vacuole in the cyto- 
plasm. As the transformation of the spermatid proceeds, the body 
becomes less significant, and in the mature spermatozoon it is no 
longer visible. Itisnot at all clear what part the body contributes 
to the formation of the spermatozoon, save the fact that it seems 
not impossible that it might constitute a part of the wall of the 
cytoplasmic vesicle. ‘The chromatoid body is very easily recogniz- 
able in almost all immature spermatozoa (figs. 47 to 50). It 
may lie where there is some remnant of cytoplasm, either in 
the region directly adjacent to the nucleus or very distant from 
it. This body likewise appears to play no important rdle what- 
soever in the formation of the mature spermatozoon, and in the 
latter it is no longer visible. It is not clear whether the body 
degenerates in situ or is expelled to the exterior from the sper- 
matozoon, as was observed by Wilson (713) in Pentatoma and by 
Fasten (718) in Cancer. 
