FERTILIZATION IN THE HONEY-BEE 237 
bases attached to the muscle layer by attenuated remnants of 
the cell walls. There is evidence that the cells tend to break 
down unevenly; during the early stages this leaves elevated 
circular ridges running around the long axis of the gland; but 
these are neither regular nor do they persist except in vague 
outlines in the final stages.' 
In the vas deferens and seminal vesicle the effect is more 
elaborate (pl. 1, figs. C, D, E,e and pl. 2 figs. 5 and 5b). Com- 
mencing at the anterior end of the vas deferens the cells break 
down unevenly and in such a manner as to leave the surface of 
the epithelium in very definite ridges. This is much more clearly 
defined and regular here than in the gland. This condition is 
described in the mature insect by Koschevnikov as ‘‘in Ring- 
walzen eingereiht”’; but a close inspection of a cleared whole mount 
or hemisection reveals an arrangement as of a spiral screw with 
four successive threads. There are about seventy turns, each 
‘thread’ making fifteen to twenty turns of the spiral, though 
occasionally one ridge ends and is replaced by a new one. As 
will appear later the function 1s apparently to increase the surface 
for attachment of the spermatozoa. The nuclei of the epi- 
thelial cells arrange themselves, not parallel to the basal mem- 
brane of the epithelium, but in a layer following the folded surface 
(fig. 5b). The nuclei retain appearances of activity and do not 
show shrunken chromatin and clear plasma as do the remnants 
of cells in the epithelium of the gland. 
The commencement of this secretory and erosive process in 
the vas deferens overlaps the period of spermiogenesis in the 
testis. As the lumen enlarges it becomes filled with fluid. The 
sperms pass into it and through it into the seminal vesicle; here 
as the sperms descend the cells also break down into a secretion. 
This process in the seminal vesicle serves three purposes: provides 
a medium for the spermatozoa by dissolution of the glandular 
elements, renders the rather firm glandular wall flexible and 
capable of considerable distention, and allows the enclosing 
muscles to act easily at the time of ejaculation of sperm. 
The sperms, still grouped in bundles as they left the cysts of 
the testicular tubules, attach themselves by the heads to the 
