318 TAKU KOMAI 
body oceurs; rarely two larger ones and a few additional minute 
ones may be present. Around the body is a narrow clear space 
which is especially marked when the body is imbedded within 
the mitochondrial body. The centrosome (c) is also near the 
nucleus; it is a minute body with no idiozome-like structure 
around it. 
The spermatid retains the above state for some time. Further 
transformation is initiated by a peculiar movement of the centro- 
some, which starts to wander toward the nucleus. It soon 
comes in contact with the nuclear membrane and further makes 
its way into the interior of the nucleus (fig. 34), until it is en- 
closed within the latter (fig. 35). The nuclear membrane seems 
to afford but slight hindrance to this movement of the centro- 
some and to give way very readily to it. The centrosome lies 
at the centre of a clear space in the nucleus, developed appar- 
ently by recession of the nuclear substance under the influence 
of the body. 
While the above change is going on, a vacuole makes its ap- 
pearance in the cytoplasm (fig. 36, v). This may occur some- 
what before the centrosome becomes enclosed within the nucleus, 
more frequently, a little later than the latter change. Some- 
times two or more vacuoles appear simultaneously (fig. 40), but 
soon they coalesce into a single one. The vacuole then enlarges 
markedly, until it occupies by far the greater part of the cell, 
so that the nucleus becomes quite eccentric in situation and 
takes a hemispherical shape (figs. 837 and 38). The mitochond- 
rial body is located on the side opposite the vacuole and lies 
over the nucleus, assuming the shape of a cupule. The above 
change in the cytoplasm may be initiated by the appearance 
of a clear space along one side of the nucleus, which space en- 
larges subsequently to arrive at the same result. Meanwhile, 
the nucleus continues to be reduced in size, while its staining 
capacity is greatly intensified. 
The centrosome now undergoes a noteworthy modification. 
The body, which has grown somewhat in size within the nucleus, 
is divided into equal halves (fig. 39). Both are imbedded in a 
common clear space (fig. 41), or each in its own space (figs. 40 
