CYTOPLASMIC INCLUSIONS OF THE GERM-CELLS 279 
and the archoplasm flow into the bead, which sloughs off, 
and take no part in the subsequent development of the sperma- 
tozoon. In Pl. 12, fig. 16, the apparatus and archoplasm have 
undergone degeneratory changes. 
10. The Case of the Rat Spermatozoon. 
Retzius (29), as we have mentioned above, does not figure 
a protoplasmic (Golgi) bead on the ripe spermatozoon of the 
rat or mouse, and apparently it would have seemed to be one 
of the exceptions to the rule that the ripe mammalian sperm 
carries a Golgi apparatus. Our friend Dr. Da Fano of King’s 
College, London, who has made preparations of the rat testis 
by his new cobalt methods, examined at our request his 
preparations of rat epididymis, with the result that he found 
that each ripe sperm does carry a small bead which impregnates 
with silver nitrate. Retzius, therefore, overlooked this bead 
in the rat sperm, and may have done likewise in the other 
forms in which he does not draw the characteristic bead. 
11. Discussion. 
(a4) On the Origin of the Acrosome in Animal 
Spermatogenesis. 
The evidence that the Golgi apparatus is in some way 
intimately associated with the formation of the acrosome or 
perforatorium has accumulated considerably within the last 
few years. 
I Paludina (12) and in Columbella (80), two molluses, it has 
been shown that the Golgi apparatus adheres to the head 
end of the nucleus of the spermatid, and before breaking 
away deposits or secretes a small granule from which the 
acrosome finally develops. In Smerinthus populi, 
a moth (10), it has been shown that the acrosome is developed 
by changes which take place in crescentic ‘ acroblasts ’, which 
we now know as the dictyosomes or individual units of the 
Golgi apparatus. In the testis of Stenobothrus viri- 
dulus we have endeavoured to follow out the formation of the 
acrosome: in this cricket it seems likely that the Golgi apparatus 
