SPERMATOGENESIS OF SQUILLA ORATORIA 317 
undergo rapid development, to produce a single large mesh 
which presses the remaining part of the network against one 
pole of the nucleus into a crescent-shaped mass (fig. 27). This 
stage is very frequently met in the course of transformation of 
spermatid; in figure 1 the middle zone consists of this stage. 
Both Grobben (’78) and Gilson (’86) mention the occurrence of 
a stage in which nuclear material assembles at one side of the 
nucleus and assumes a crescent shape. This apparently refers 
to the stage just described. 
When further change sets in, the chromatin substance begins 
to diffuse into the single large mesh, so that the latter dimin- 
ishes gradually in size (figs. 28 to 30) until finally it disappears 
altogether and the nucleus comes to stain uniformly dark (fig. 
31). During the progress of the change, the size of the entire 
nucleus diminishes somewhat, and a clear space develops around 
it. Soon, however, the nucleus enlarges, its consistency reduced, 
and its power of taking stains decreases, so that it comes to 
stain grayish in iron-hematoxylin (figs. 32 and 33). The suc- 
cessive transformation stages of the spermatid nucleus described 
above may be found in a single slide and is not very hard to 
follow. Similar changes were traced by Spitzchakoff (09) in 
the spermatogenesis of Leander; thus my figures 27 and 28 
apparently correspond with his 5 to 7, my figures 29 and 30 
with his 8 and 9, and my 32 and 33 with his 10, respectively. 
The spermatid (fig. 33) is now polygonal and contains a 
spheroidal nucleus at the center. The nucleus appears finely 
granular and has a rather loose consistency, its appearance 
somewhat reminding one of a ball of wool. The outline of the 
nucleus is often rather indistinctly defined. In cytoplasm is a 
mass with a granular appearance representing the ‘mitochondrial 
body’ (m) of authors on the spermatogenesis of the Decapoda. 
The body lies, in the majority of cases, where there is the great- 
est space between the nucleus and cytoplasmic wall, ‘presenting 
frequently a crescent shape and stains with basic dyes usually 
somewhat more weakly than the nucleus. The cytoplasm 
further contains the chromatoid body (&), which has nearly the 
same appearance as seen in preceding stages. Usually only one 
