452 
j. bront£ gatenby. 
phobe fluid similar to the same substance inside the mito- 
chondrial body; the ultimate use of this region in the 
acroblast is also similar to that of the mitochondrial chromo- 
phobe zone. It enables the acroblasts to fuse readily, and is 
very probably in some way connected with the formation of 
the acrosomic granule. The latter seems to be the essential 
organ in the formation of the sperm head, and the acroblasts 
are the vehicles whereby it is secreted. From the manner in 
which the granule appears it is extremely likely that the 
nucleus is the prime factor in the secretion of this body. The 
manner of origin of the acroblasts is unknown to me ; they 
can only be found with certainty at the time the spermatocyte 
is fairly well advanced in growth period, but one is justified 
in assuming that the matter or bodies from which the acro- 
blasts originate is represented in the spermatogonium. It may 
be possible, with improved technique, definitely to identify 
acroblastic material in the latter cell ; exactly what becomes 
of the acrosome in fertilisation is not properly understood, for 
the current idea that it degenerates may not be true. Instead 
one might be justified in assuming that the acid and alcoholic 
fixatives destroy it, and cause it to be invisible just as the 
same media do in growth stages of the male germ-cell. Until 
this matter has been completely examined with suitable 
technique we are not justified in paying no attention to the 
acrosomic body after entry of the sperm. It may be true that 
the acrosome persists in some way or other, but the point I 
wish to emphasise is that we cannot tell whether it does or not 
until we use proper methods . 1 Carnoy, Petrunkewitsch and 
such fixatives are not suitable for this work. 
It has occurred to me that the acroblasts may be mito- 
chondrial bodies of a modified nature, but I have little 
evidence at present either way. The number of the acro- 
blasts seems to vary somewhat, and they may well be mito- 
chondria which have not absorbed the chromophobe zone. 
1 For similar view see F. Payne, ‘ Journ. Morph.,’ vol. 28, No. 1, 
p. 311. 
