328 GILMAN A. DREW 
eggs were far from mature. This, together with the dormant 
condition of the sperm in the receptacle, and the fact that they 
seem to be poured out only during egg laying, point to a possible 
long retention. It is certain that the same female may have 
sperm reservoirs attached near this receptacle a number of times 
after it has been filled, and it is possible that the same sperm do 
not continue long in the receptacle. There seems, however, to 
be no evidence that they are discharged except during the period 
of egg laying. at 
The other method of copulation results in fastening the sperm 
reservoirs of the ejaculated spermatophores near the end of the 
oviduct (fig. 8, s) usually directly on its walls but sometimes on 
the mantle, gill or visceral mass. There is no special receptacle 
for the sperm from these sperm reservoirs. They escape into the 
water, becoming active as they escape, and pass out with the water 
through the funnel. The escape of the sperm is rather rapid but 
there are vast numbers in each reservoir, from which they are 
constantly poured like smoke from a chimney until the reservoir 
is empty. It is not known how long it takes to empty a reser- 
voir but by keeping reservoirs from spermatophores that ejacu- 
lated in dishes of sea-water, and by examining reservoirs normally 
attached to the oviducts and buccal membranes of females, it 
seems probable that the sperm do not all escape for two or more 
days. 
In aquaria I have seen rather more cases of copulation where 
the spermatophores are inserted into the mantle chamber than 
where the sperm reservoirs are attached to the buccal membrane. 
This may be because of the limited quarters in aquaria. In the 
larger floating tanks, in which specimens are sometimes kept be- 
fore they are brought into the laboratory, the buccal membrane 
copulation seems proportionally more common than in aquaria, 
but even here the mantle chamber copulation seems to be rather 
more frequent. 
The same individuals may copulate several times in the course 
of a few hours. In general the male is aggressive. The female 
may attempt to escape or she may be quite passive. Spermato- 
phores seem to be inserted in the mantle chambers of only those 
