250 
E. A. ANDREWS 
into its usual position, then letting the stylets recede to their 
usual horizontal position and finally letting go of the claws of the 
female. 
As soon as the claws of the female are released she returns to 
the customary position with the ventral side down and keeps this 
with great persistence except in the processes of egg-laying and 
turning, elsewhere described by me. 
Though the stylets are the essential ducts for the transfer of 
sperm, it was found that when they had been cut off entirely the 
male would still carry on the preceding stages of conjugation and 
even contract the abdomen as if thrusting forward the stylets 
that were not there. While the series of events in conjugation 
may be thus carried on for a long time, though the end events 
will be impossible, it is also true that the series may go on for a 
while when the first part is lacking, or at least but dimly repre- 
sented. Below it will be shown that the series may go on when a 
middle factor, the fastening of the hooks is omitted by the removal 
of the hooks, which prevents the success of the final acts, though 
they are attempted. 
The experiments that show that the perfect expression of the 
first of the series is not necessary for the carrying on of subsequent 
parts were as follows: Ten males and females with chelae tied 
shut by elastic bands were kept separate for several days in water' 
at 20 degrees C, though in December. When the females were 
put in with the males, each in his accustomed dish, the males 
acted individually, but most of them tried to seize and turn the 
females. The males generally remained quite inert till touched 
by the female crawling about in the strange dish, but a few males 
rushed at the females before being touched. That they tried 
to turn the females was seen in the pressure exerted by their 
claws and turning of their own bodies. The females and males 
fenced together, or the former sprang backward, as if their claws 
were not bound, except that there was not the usual open claw 
and pinching. Without this seizure the males did not succeed 
in turning the female, though one nearly did so and proceeded to 
mount upon and embrace the female, though the claw grasping 
stage was lacking. When the females were bound with the legs 
