ANDREWS: ANNULUS VENTRALIS. 
445 
and leads to the complete packing of the recess and tube of the trumpet 
with sperms that fill out all the cavity, and as seen in figures 16, 17, 20 
(pi. 45), and 27 (pi. 47) the mass is largely composed of actual sperms 
separated from one another by but a little clear matrix. That this 
mass of sperm flowed in under pressure seems to be indicated by the 
arrangement in curved lines, especially when the stream of sperms 
passing over the rim (that juts out to bar partly the passage from the 
tube into the recess) spreads out in whirls in the recess. This is 
shown in figure 17 (pi. 45) which represents the end of the tube and 
the recess cut in vertical section with the rim or bridge projecting 
into the passage and apparently affecting the distribution of the 
sperms. A greater magnification of part of this mass shows, as in 
figure 22 (pi. 46), that the sperms are not in actual contact with one 
another but are imbedded in a clear matrix and for the most part they 
are flattened rounded disks many of which stand on edge in this paraf¬ 
fin section. This is about the normal appearance of sperm in the 
testis and vas deferens before water has acted upon it, as else¬ 
where described (Andrews, :04a). 
The preservation of the sperm in its natural shape after the transfer, 
depends upon the anatomy of the annulus and also upon the action 
of the male, both factors being necessary to keep the sperm sealed 
away from the water. In the anatomy of the annulus we recognized 
a curved trumpet with open mouth and a curved slit along its entire 
length. This slit, however, seems to be closed up water-tight until 
the eggs are laid. Its sides are very closely in contact and at the 
suture the cuticle seems to occlude the opening of the slit though this 
is difficult to be sure of, as the action of reagents and of pressure easily 
opens the slit and a view of an undisturbed suture is hard to obtain 
with high powers. It may well be that naturally the cuticle passing 
down into the slit on each side of its cavity, may be in such close con¬ 
tact with the cuticle of the opposite side as to exclude the water, 
though in sections, as figures 8 (pi. 43) and 14 (pi. 44), the slit is 
widely open. 
Excluding the water from the mouth of the trumpet, there is a 
large mass of wax-like material that is forced in like a stopper of 
soft rubber into a bottle. This wax plug is furnished and inserted 
by the male. It is indicated in figures 14 (pi. 44) and 28 (pi. 47). 
It fills out the vestibule and protrudes more or less out of the orifice 
and at the inner end projects into the first part of the trumpet tube 
