4 ROBERT H. BOWEN 
adopted the term acrosome. ‘The acrosome increases in size, 
becoming a large, clear vesicle, to the surface of which the remains 
of the acroblast are attached (figs. 6 and 7). The centrioles pres- 
ently become conspicuous, being sharply stained with Fe-hema- 
toxylin. They are always located in the neighborhood of the 
acroblast (figs. 6, 7, and 8); indeed, they seem often to be resting 
on its surface. The relation seems, however, to be purely a 
topographical one. 
When the acrosome has reached a certain stage, it becomes 
applied closely to the nuclear membrane, and gradually the cell 
wall is drawn down over it, creating the impression that the 
acrosome has actually protruded through the cell wall (fig. 8). 
Throughout this period of fixation, the acroblast remains close 
to the acrosome (figs. 8 and 9), but the connection between the 
two has obviously become very loose. In fact, the acroblast 
or, as it may now be called, the Golgi remnant, becomes more or 
less spread out or broken up into separate masses (fig. 9), 
and in Fe-hematoxylin preparations is usually not to be made 
out at all. This loss in staining capacity is obviously the 
source of Meves’ erroneous description of the disappearance of 
the ‘Sphaerensubstanz.’ 
The Golgi remnant, together with the centrioles, lingers for a 
time in the immediate vicinity of the acrosome, and then both 
are shifted to the opposite pole of the nucleus establishing the 
future long axis of the sperm. Everything indicates that 
McGregor was correct in holding that the separation of acrosome 
and centrioles is due to the active migration of the centrioles, 
rather than of the acrosome, as Meves contended. 
The spermatid nucleus meanwhile becomes very irregular in 
shape and then begins to draw out to form the head of the sperm 
with the acrosome at one end and the centrioles at the other 
(fig. 11). The Golgi remnant lies in the cytoplasm at the base 
of the head close to the centrioles (figs. 11 and 12), becoming 
oftentimes more or less broken up and diffuse. It is easily 
demonstrated by the special methods for the Golgi apparatus, 
but not by the usual Fe-hematoxylin techniques. The Golgi 
remnant remains in this same position for a long time; indeed, 
