.432 J. BttONTlL GATENBY. 
taken part in every cell division, lies in no definite position; 
it grows a good deal, but its staining reactions do not appear 
to alter at all. I mention this especially because there was 
always the possibility that it might have become less or more 
densely staining in sympathy with the chromatin of the 
nucleus. In PL 23, figs. 4-8, and PI. 24, fig. 19, the body is 
shown in the various positions in which one may find it. In 
PI. 23, fig. 9, a metaphase of the first spermatocyte division 
is ehown, the micromitosomata being far apart (31.). In 
fig. 18 of PL 24 a Flemming-fixed spermatocyte in the early 
prophases is shown, in order to illustrate the micromitosome 
(M.) apparently in division; this body is constricting, and 
before the asters have moved one on each side of the nucleus 
it will have divided. In fig. 18 the micromitosome is swollen 
by the acetic acid of the strong Flemming solution 
This cell is particularly interesting, for it appears to prove 
that the micromitosome does divide without the intervention 
of the amphiastral rays. In the case of the spermatogonial 
division it is fairly certain that the micromitosomata are not 
directly affected by the astral rays, and the same may apply 
in the case of the spermatocyte division. 
One can find numerous cases where the micromitosomata 
have reached the opposite ends of the cell before the two 
daughter cells have begun to constrict. This seems to point to 
the fact that these curious bodies are separated one from the 
other by cytoplasmic currents. In PL 23, fig. 9, one focussed 
down upon the micromitosomata before one came to the chromo- 
somes. In the spermatocyte anaphase the micromitosome 
generally appears to keep well within the zone of influence 
of the centrosome, as PL 23, fig. 10, shows, and I do not 
remember having seen these bodies very far removed from 
the aster at this period. In the second spermatocyte division 
(PL 25, fig. 34) the micromitosome behaves as in the first 
maturation division, and in the newly-formed spermatid 
always lies near the nucleus (PL 23, figs. 12 and 13). 
When the spermatid begins to metamorphose the micro- 
mitosome may be orientated in any direction ; e. g. in Pl. 23, 
