CYTOPLASMIC INCLUSIONS OF THE GERM-CELLS 981 
acrosome has reached almost its greatest size; the natural 
inference being that the Golgi apparatus and not the nucleus 
is concerned with the growth and perfection of the rudimentary 
acrosome. In this connexion it will be remembered that one 
of us has shown in Smerinthus (10) that the acrosome may 
form completely, while the nucleus lags behind in development, 
as occurs in degenerating spermatids. 
We conclude at present that the animal acrosome is formed 
directly in association with the Golgi apparatus, and that the 
nucleus has little if any influence in the process. 
(b) The Middle-piece of the Spermatozoon 
after Entry into the Egg. 
That the middle-piece of the mammalian spermatozoon is 
carried into the egg is well known, and it is now established 
by the work of van der Stricht (31), Lams (16), and Levi (19), 
that excepting the centrosome the entire middle-piece of 
Vespertilio and Cavia, after having become carried bodily 
into the egg, remains inert and complete, and is passively 
borne into one or other of the two blastomeres (or one of three 
in Levi’s case), and is ultimately lost sight of, probably de- 
generating at a later stage in the cleavage of the egg. 
Lams’ (16) work is particularly worthy of mention. Alone, 
and also in conjunction with Doorme, he showed that in the 
white mouse and the cavy the middle-piece (excepting the 
centrosome) remains unchanged after entry into the ovum. 
Many of the figures of Lams show the mitochondria lying 
upon the middle-piece, but in no case did he find any activa- 
tion of these bodies. In both the cavy and the rat we are 
aware that the middle-piece bears a Golgi bead, but since 
Lams used no methods for the Golgi apparatus, it is hardly 
justifiable to use his work as evidence with regard to the 
behaviour of the Golgi bead after introduction into the 
ovum. 
Henneguy, at the discussion following Lams’ communication 
to the Brussels congress of 1910, suggested that the blastomere 
