478 
J. BRONTE GATENBY. 
failure of the nucleus in the metamorphosis of the cell 
elements of the spermatid the centrosome invariably retains 
all the energy necessary to undergo its normal changes. 
One is forced to believe that the central corpuscle of all the 
plasmatic elements is the most resistant to those influences 
which cause abnormality, and this should be borne in mind 
in the discussions relative to any possible part played by 
<c apyrene ” spermatozoa. 
Discussion. 
The main fact which we must keep before us in a review of 
the evidence provided by these abnormal stages is that it 
would be unwise to conclude, because one body is somewhat 
far removed from another, that mutual influence is so pre- 
cluded. Because the centrosome lies at the head of the 
atypical sperm, and the abnormal nuclei and their acroblasts 
far down, we are not justified in at once dismissing any 
possibility of the one affecting the other. Nevertheless I 
feel that we can conclude a good deal from such evidence as 
we have at hand, though some suggestions must only be very 
tentative. I have already shown that though the nuclear 
matter is abnormally affected, still the acrosome may be 
formed, and in the same way a normal macromitosome may 
be developed from the granules. The tail of the sperm may 
be normally formed by a thinning out and elongating of the 
macromitosome, and otherwise, excepting the chromatin, the 
cell elements may be quite normal. I believe that this shows 
that we are concerned with two special occurrences in sper- 
matogenesis : Firstly, the formation of the acrosome near the 
nucleus, and the evident inter-relationship of these bodies ; 
and secondly, the growth of the tail filament, and the special 
grouping of, or formation of, an envelope from the mito- 
chondrial granules. These two separate occurrences appear 
to be able to take place with independence of each other, and 
I think the two apparent free forces in the spermatid are 
respectively lodged in the nucleus and in the centrosome 
