282 E. A. ANDREWS 
that carry the tips of the first back and forth a part of a milli- 
meter only. When the tips of the stylets have gained entrance 
into the annulus, these thrusts may serve to introduce the tip far- 
ther into its cavity. As in the movements of recession the force 
here must be exerted by the muscles of the abdomen, as the sty- 
lets themselves have no telescopic power; and actual twitching 
of the anterior part of the abdomen were seen. 
SPERM EMISSION AND CONDUCTION 
In normal conjugation nothing is seen of the sperm so that its 
transfer from the deferent duct to the cavity of the annulus is a 
matter of inference. The papilla is applied to the orifice of the 
tube of the first stylet so that it may discharge into it and sections 
show the tube full of sperm, (figs. 14, 15); moreover in some abnor- 
mal cases the sperm is seen to issue from the tip of the canula into 
the water, and, as the tip of the canula is normally inside the 
sperm pocket, it is evident that the sperm must pass along the 
stylet from the papilla. The force that propels the sperm is no 
doubt muscular contraction, but it is not clear at first what mus- 
cles are concerned; there are none within the first stylet which 
acts merely as a passive tube. 
From such figures as 2, it is evident that the deferent duct has 
powerful transverse muscles that could squeeze out the sperm with 
force and this seems the main if not only motive force to carry 
the sperm through the papilla and all along the tube of the stylet 
into the annulus. 
The force necessary to propel the liquid sperm through a tube 
that is only some 20 to 40 u in diameter (figs. 18, 15) is great and 
attempts to force india ink through the tubule of the stylet with a 
small hypodermic syringe failed. When the specially ground can- 
ula was inserted into the orifice, while the radius was engaged in 
the tubule, no ink could be forced out of the tip of the stylet. 
It was inferred that the radius blocked the way, as it fits in so as 
to nearly occlude the lumen (fig. 8), but the same failure was met 
with when the triangle was removed from the stylet, but then the 
ink jetted out along the proximal part of the groove where the 
