FERTILIZATION IN THE HONEY-BEE 249 
the sperm through the penis in ejaculation, the mucus has forced 
all the residual sperm out of the penis, so that whatever material 
is not injected into the female organs, and is thus to be lost when 
the penis is dropped, will not be the physiologically more valuable 
spermatic fluid. 
2. Correlation of age with functioning. With the foregoing 
facts in mind, we may follow the differences in the response of 
the sexual mechanism, at different stages of development, to 
artificial or natural stimuli. In a young drone (up to four or 
five days) the chitinous blind end of the ejaculatory duct is 
still reenforced with layers of glandular and hypodermal cells; 
the walls of both mucous gland and seminal vesicle are stiffened 
with unresolved glandular epithelium; the sperms are either still 
in the testis tubules or are firmly attached to the vesicular wall, 
and are incapable of the activity which later characterizes them, 
~ and it is doubtful whether the valve which eventually occludes 
the gland’s lumen is in the early life of the drone capable of 
doing so, for since the lining of the basal portion of the gland is 
the last to be resolved into secretion, this valve is still stiffened 
by a heavy glandular coat. The result of stimulating drones 
less than four or five days old is either no secretion at all when 
the organ is extruded or a secretion composed entirely or in 
large part of mucus, or if sperms are present, the glandular wall 
of the vesicle has pulled away with them, and the sperms are 
inert or vibrate their filaments but feebly. 
After the fifth or sixth day the reaction is markedly different. 
The reinforcing cells over the end of the ejaculatory duct have 
withdrawn; the mucus is more viscous; the sperms release them- 
selves more and more readily from the vesicle and are extremely 
active; the glandular walls of the organs are thin and pliable, 
and the sperm content of the vesicle is discharged through the 
ejaculatory duct ahead of the mucous content of the accessory 
gland. The whole reaction of the drone is also more violent and 
spasmodic. These conditions, while virtually established, as 
stated, at five or six days of age, seem to become accentuated up 
to the age of nine or ten days, although the morphological and 
histological changes after the sixth day are slight and although 
