THE DEVELOPMENT OF THE SPERMATOZOA, 423 
superficial cells, which have now become blastophoral cor- 
puscles. 
When the time comes for their being shed the bundles 
are thrown off and break up, leaving the blastophoral cells 
behind, which afterwards atrophy by degeneration and 
breaking up of the nucleus, and are thrown away. 
General Considerations and previous Literature relative to 
Spermatogenesis.—The point on which I wish to lay stress in 
the previous observations is the existence of a blastophoral 
cell, which, from the cases I have taken by chance for study, 
and the figures in the papers of other writers, seems to be of 
very general distribution. The question naturally arises, 
What is its morphological significance ? 
When I found the body in the earth-worm Professor 
Lankester told me of a suggestion which had been made to 
him by Professor Van Beneden, of Liége, viz. that it 
corresponded to the ovum whilst the spermatoblasts corre- 
spond to the polar vesicles or directive corpuscles which 
are thrown off from the ovum previous to fertilization. 
These bodies, of very general occurrence, are hard to explain. 
Balfour (this Journal, vol. xviii, p. 123) says, “ I would sug- 
gest that in the formation of these polar cells, part of the 
constituents of the germinal vesicle which are requisite for 
its functions as a complete and independent nucleus, are 
removed to make room for the supply of the necessary parts 
to it again by the spermatic nucleus,” and it may be that as 
the polar cells represent the elimination of a male element 
from a cell whose future destiny is female, so the formation 
of the blastophoral cell represents the same ridding of the 
female element from a cell whose destiny is male. 
After the publication of a paper “On the Development of 
the Spermatozoa of Lumbricus ” (this Journal, April, 1880), 
I received a paper from Mr. Minot, published in the ‘ Ameri- 
can Naturalist’ for February, 1880, in which, from theo- 
retical considerations, he arrived at the conclusion that some 
such structure as the body alluded to above must be found 
- in the development of the spermatozoa, and records Semper’s 
‘Observations on the Development of Spermatozoa in Elas- 
mobranchs” in support of his view, in which Semper de- 
scribes a part of the original cell which is left behind as 
“ Mutterkern,” though it is evidently the same as our blasto- 
phoral cell. 
The considerations offered above are, of course, pure 
speculations, and it is quite possible that these blastophoral 
cells have no morphological significance, but function as 
bodies for the support and nutrition of the young sperma- 
