248 
E. A. ANDREWS 
all nearly the same diameter it is finally possible for the male to 
catch the hooks into the joints of the female as indicated in the 
diagram of a section of the two conjugating animals (fig. 2). 
Really it is only the base of the legs that are in contact, since the 
ventral side of the males is hollowed out, as represented in the 
diagram by the groove lined with setae. And in this groove lie 
the two pairs of appendages of the male that are soon to be used. 
The hooks hold so firmly that lifting the male out of the water 
lifts the female also, and indeed it is impossible to separate the 
two without unlocking the hooks. 
Usually all the stages of preparation so far considered, including 
the hooking, require but a few minutes, but with great individual 
differences. 
With the male and the female firmly locked together and the 
stylets held at an angle of about 45 degrees, the transfer of sperm 
can take place after the muscular efforts of the male have forced 
the tip of the first stylet into the firm orifice of the annulus of the 
female. To accomplish this the two animals must be quite 
accurately adjusted and this requires some trial. There is more 
or less advance and recession of the body of the male along the 
female till the tips of the stylets find the mouth of the sperm 
receptacle. In these trials there is sometimes seen a rapid play 
of the setose tips of the third maxillipeds, quick sidewise and 
lengthwise motions over the bases of the legs of the female. It 
seems that some information may be acquired by the male by this 
palpation. 
To obtain actual entrance of the tip of a stylet into the recept- 
acle, force is finally exerted by violent contractions of the muscles 
of the male. The posterior part of the abdomen of the male 
grasps the coiled-up end of the abdomen of the female as a hand 
about a ball (fig. 7) and tends to hold these ends of the animals 
together. And at the front end the chelae hold the claws of the 
female. Between these two points the hooks (fig. 2) bind the two 
animals immovably. When the abdomen contracts the long 
chelate legs also contract without loosing their hold and they tend 
to straighten out. This elongation of the chelate legs tends to 
. throw the head of the male up away from the female. As the 
