ORGANS FOR SPERM-TRANSFER 285 
illa (fig. 2) or those along the tubule itself (fig. 8). Possibly this 
preparatory action of the radius is all that it has to fulfill and that 
the pressure of the muscle of the efferent duct is all sufficient 
to cause the sperm to run through the length of the stylet. In. 
connection with this question we have to bear in mind that the 
sperm is in some way freed from its envelope of secretion made in 
the efferent duct before it is laid away inside the sperm pocket 
where it exists pure (1). 
This separation of sperm from enveloping secretion takes place 
in the tubule of the stylet. In the proximal part of the tubule the 
secretion of the deferent duct (fig. 2), is still all around the strand 
of sperm (fig. 14), but distally the sperm is almost pure inside the 
tubule (fig. 15). 
We found also that in one case a male, fallen on the side while 
still holding a female, had the stylets only partly erected so that 
they were free in the water and from the tip of each canula a very 
fine stream of sperm, finer than the tip of the spatula, issued slowly 
and coiled up in a small mass. From one canula the sperm then 
slowly sank in ten minutes down in the still water as a fine thread 
with a coil at the tip. Another male showed faint sperm jelly 
on the tip of the flagellum of the endopodite of the second stylet 
and this was pure sperm becoming modified by the water; there 
was no secretion. 
There are however besides these escapes of pure sperm, escapes 
of sperm inside of secretions that resemble spermatophores. In 
a male, in which the triangle was in the position of recession, (fig 
31), there were such white sperm threads, $ to 1 mm. long, about 
the orifice of the groove. The pseudo-spermatophores that in 
abnormal or interrupted conjugations were sometimes seen were 
soft, paste-like tubes containing a central mass of sperm. The 
short pieces of tube stick by their ends to the inside of a pipette 
used to pick them up and to the shell of the crayfish on which they 
fall. 
The wall of these tubes is a very thin layer of secretion which 
is vesiculate and stringy like dough and can be drawn out into 
clear threads with minute droplets along them. These would 
seem to be not normal spermatophores, which in Astacus have 
