398 GILMAN A. DREW 
they are held in position by the male long enough for them to 
discharge and to have the sperm reservoirs fixed by the cement 
on them to the tissue near the oviduct of the female. In this 
position each gives out its small cloud of sperm for some hours. 
If the female lays her eggs within the time they are active, in- 
semination is assured. On the other hand, if the spermato- 
phores are transferred to the region of the buccal membrane 
of the female, they are held in position by the male until they 
discharge and the sperm reservoirs are attached to the walls 
arranged for them. Here, as they discharge, the spermatozoa 
are directed, evidently by ciliary action, into the sperm recep- 
tacle where they are stored for future use. 
The discharged empty case (fig. 16) is much smaller, especially 
in diameter, than it was before ejaculation. The outer tunic 
appears about as it did. The middle tunic is clear, not granu- 
lar, and occupies most of the space inside the outer tunic. The 
evaginated tube that adheres to the oral end of the outer tunic 
is likewise less in diameter than it was at the time of evagination 
when there was pressure inside. The end of the tube attached 
to the outer tunic is clear and corresponds to the oral unorna- 
mented portion of the tube in the spermatophore. The region 
of the spiral filament is shown by the broken fragments adher- 
ing to the tube, and the outer end of this marked portion 
represents the end of the spiral filament and inner membrane 
that was attached to the oral end of the cement body. This 
is the point of rupture (PR). The remaining unornamented 
flaring tube is the part of the middle membrane which was in 
contact with the cement body. The outer third of this portion 
was firmly attached to the inner membrane that covered the 
cement body. By the breaking of this attachment the sperm 
reservoir, with the cement at the closed end, became free to 
be forced out of the case by the pressure behind it. 
