PLATE 2 
EXPLANATION OF FIGURES 
9 Extremity of the evaginating portion of a spermatophore at the instant 
the cement body has reached the end of the nearly evaginated ejaculatory ap- 
paratus. The inner membrane and spiral filament have broken from the tip of 
the cement body and are seen at the limit of ornamentation on the outside. The 
middle membrane adheres closely to the cement body, but the pressure from 
behind has not yet caused the cement body to change shape. > 70 diameters. 
10 A portion of the evaginated ejaculatoy apparatus of the same specimen 
shown in figure 9, taken some distance from the oral extremity, at the point 
where the thickened portions of the outer membrane and inner tunic now lie. 
Evagination has turned these membranes back on the inside of the ejaculatory 
apparatus where they now form a reservoir wall into which the disorganized 
sperm mass is being forced. X 70 diameters. 
11 Extremity of the evaginating portion of the spermatophore an instant 
later than shown by figure 9. The pressure from behind has caused the adher- 
ing middle membrane to draw out the oral portion of the cement body at the 
sides. X 70 diameters. 
12 A whole spermatophore shown at a stage of ejaculation just a little more 
advanced than shown by figure 11. For convenience in placing on the plate the 
spermatophore is drawn as if cut in two parts. The position of the sperm mass 
which is being forced through the evaginated ejaculatory apparatus is shown. 
x 20 diameters. 
13 Extremity of the evaginating portion of the spermatophore shown in 
figure 12. This is an instant later than the stage shown by figure 11. The ad- 
hering middle membrane has drawn the cement body out to form a cap over 
the end of the sperm mass which is being forced against it. XX 70 diameters. 
14 A slightly later stage than that shown by figure 13. X 70 diameters. 
15 Extremity of the evaginating portion of aspermatophore immediately after 
the pressure has caused the cement body, to which the middle membrane has 
adhered, to burst the inner membrane which has confined its viscid cement ma- 
terial. This act at once liberates the cement, which is spread over the end of 
the reservoir wall that encloses the sperm mass, and frees the reservoir wall, 
which consists of the outer membrane and inner tunic, now stretched and forced 
together so their individuality can no longer be distinguished, so it may slip out 
of the evaginated middle membrane, against which the outer membrane lies. 
< 70 diameters. 
16 The empty case, consisting of the outer and middle tunics, and the evag- 
inated middle and inner membranes with the broken fragments of the spiral 
filament, after the sperm mass with the enclosing membranes and cement have 
been discharged. XX 20 diameters. 
17 Thesperm mass with the enclosing membranes and with the cement spread 
over the closed end, after being ejected from the case. This mass may be called 
the sperm reservoir. The walls consist of the stretched outer membrane and 
inner tunic, which are open at the pointed end. Here spermatozoa leaves as 
they are mixed with sea-water and become active. The cement hardens in sea- 
water and sticks the reservoir in place. The thickened portion near the open- 
ing, with the constricted portion immediately beyond it, is characteristic of 
the reservoirs. It may have something to do with the thickened portions of 
(Continued on page 426) 
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