602 
Proceedings of the Royal Society 
and not in motion. I have not yet been able to work out com- 
pletely the process of spermatogenesis, but it seems that the cells of 
the testicular capsules send off processes, each of which becomes a 
spermatozoon. Only two or three of these processes are formed at 
a time, and the spermatoblast seems to develop a number of sper- 
matozoa in succession, instead of, as in nearly all other cases, simul- 
taneously. The spermatozoa have a pear-shaped head, and a long 
tail, which is attached to the obtuse end of the head. 
I venture to suggest the hypothesis in explanation of the above 
facts, that the males are nothing more than supplementary males, 
and that the Myxine in its young state is nearly always, if not 
always, hermaphrodite. It is evident that, as the spermatozoa are 
developing in the hermaphrodites while the eggs are still very small, 
self-fertilisation is impossible ; but it seems extremely probable that 
the hermaphrodites while young act as males, and that most eggs 
are fertilised by them. The females with large eggs are never herma- 
phrodite, and it may be inferred that as the eggs develop the testi- 
cular portion of the reproductive organ disappears. There may be 
some females which never possess a testicular portion, as there are 
perfect males, but of this I cannot be certain. If the above hypo- 
thesis be correct, it would account for the extreme rarity of perfect 
males. Another fact, which is partially accounted for by my in- 
vestigations, is the extreme rarity of female specimens with ripe 
eggs. The eggs are certainly deposited in winter, and eggs approach- 
ing maturity are not to be found in the summer months. But even 
now the specimens with eggs nearly ripe bear a very small propor- 
tion to the total number obtained, and it is probable that the 
animals, when just preparing to shed their sexual products, cease to 
feed, and therefore cannot be allured by bait to either hook or trap, 
which are the only known methods of capturing them. One thing 
deserves to be mentioned with reference to the male elements. In 
the hermaphrodites, in which spermatozoa were being developed, 
the total size of the testicular portion of the generative organ was 
extremely small, compared to that of the testis in all other verte- 
brates, and the quantity of milt shed, unless a sudden development 
takes place at the last moment, must be extremely small. This 
fact seems to indicate that fertilisation does not take place in the 
open water, and it is possible that the eggs and milt are shed in the 
mud in which the animal lives. 
