248 W. HAROLD LEIGH-SHARPE 
The large specimen upon which the following experiments 
were tried a day or so after it was caught was obtained at Ply- 
mouth in June, 1918, being only the second brought to the 
laboratory there that year. In this the siphon was 3 inches 
long. 
The first explanation that would probably occur to an observer 
as to the use of the siphons is that the spermatozoa were either 
contained and stored in them or drawn into them previous to or 
during copulation. 
My attention, indeed, was first attracted to the subject by 
the verbal statement of my valued former tutor and friend, 
Mr. J. T. Cunningham, the well-known authority on fishes, 
that ‘‘no spermatozoa had ever been found in these sacs at any 
time.” After five years of examination of some hundreds of 
S. eanicula, at all times and seasons from various parts of British 
coasts, I fail to record the observation of any spermatozoa in 
the siphons of any animal studied, whether of this or other 
species, or, indeed, of any contents whatever, parasites included, 
except, on two or three occasions, this S. catulus being one of 
them, very slight traces of what looked like mucus, but may have 
been decomposition débris, or exuded by the wall of the sacs 
themselves. I most strongly, therefore, endorse his proposition. 
At the same time the walls of the siphon are so very muscular 
as to suggest the injection and expulsion of fluid of some sort, 
so I was reduced to considering whether or not that fluid might 
be merely sea-water. The siphons appear so early in develop- 
ment, in fact as early as the claspers, and are present in a young 
fish immediately after hatching, as also are the claspers in the 
male (fig. 3), that this seems evidence that they are correlated 
with them. 
Accordingly I performed the following experiment: The 
finely drawn-out end of a ball-pipette, similar to those used for 
filling fountain-pens, was introduced by way of the apopyle, 
which, in the natural position of the claspers, is open, into the 
aperture of the siphon sac which is extremely narrow. ‘The 
pipette previously filled with an ordinary injection fluid of 
powdered carmine in suspension (containing a small quantity of 
