ORGANS FOR SPERM-TRANSFER 247i 
USE OF STYLETS IN CONJUGATION 
The way in which the various parts of the stylets are used in 
the process of conjugation and sperm transfer has been found out 
partly by direct observation, partly by experiment, and partly 
by more indirect inferences that still leave some questions un- 
answered. 
The phenomena of conjugation in general have been described 
elsewhere (5) and we will here consider chiefly the use of the sty- 
lets. There is a stage in the early part of conjugation, where the 
male has seized the female and clasped all her claws, when he 
rises up away from her sufficiently to allow the pleopods to swing 
back and forth. In this swinging the long stiff stylets and acces- 
sory stylets take part and then are soon locked together, after 
which the stylets are held by the crossed fifth leg so that hence- 
forth they make a rigid mass which cannot be folded down against 
the thorax again by any pressure until that fifth leg is removed. 
The process of locking together of the stylets is as follows: 
The swinging of the pleopods is caused by their basal muscles; 
and likewise the muscles in the bases of the stylets move them 
slightly backward, or erect them, and forward, or depress them. 
While both first and second generally move together and right 
and left alike, they have been seen to move independently. By 
a special movement of the second stylets they are clasped against 
the first in such a way that the triangle is applied to the neck of 
the first stylet. By arching the abdomen, cat-like, the second 
stylet is drawn up dorsally along the first, and then, by partial 
relaxation of the arch of abdomen, the second is shoved distally. 
along the first, while held tight against it; the result is that the 
wedge glides along in the groove of the stylet and the radius enters 
into the inner tubule through the flaring orifice and is shoved in 
so far that it remains fast. In sections (fig. 8) it is seen that radius 
fits into the groove as in a socket and, all the walls being thick and 
solid, the radius cannot be forced out again without running it 
back along the orifice. The fact is that the locking is very firm 
and when one tries to pull the second stylet backward the first. 
is dragged with it and only by pulling the second dorsally toward 
