FERTILIZATION IN THE HONEY-BEE 2 
complete extrusion of the penis with ejaculation of spermatic 
fluid. Removing the abdomen from the thorax before dissecting 
lessens the effect; reducing the temperature also renders old 
drones less irritable (but young ones, three days old, more so). 
Slow injection of all fixatives containing acid causes contraction 
of gland and vesicle, with bursting of the gland or extrusion of 
contents through the ejaculatory duct. 
More satisfactory results with Bouin’s fluid finally led to the 
use of picric acid for killing, and the best results were obtained 
by injecting cold saturated aqueous picric acid solution through 
a fine-drawn pipette into the side of the thorax just beneath 
the wing, forcing the fluid in very slowly until the abdomen 
became slightly distended. This seemed to be effective partly 
through inhibiting the stimulation of the sex organs by the 
ganglia in the thorax, since indications of stimulation by these 
ganglia were observed before the irritant that was being injected 
could have reached the abdomen. Chloroform, ether, and 
cyanide were not satisfactory as anaesthetics to prevent distortion. 
By rapidly opening a freshly cut-off abdomen under the low 
power of a binocular, the parts may occasionally be exposed 
quickly enough to allow of observation of the activity of the 
organs. ‘The abdominal pressure that might force the penis to 
extrude is in this case eliminated by opening the abdomen, so 
that muscular contraction of the walls of gland and vesicle is 
the effective agent of the activity that follows. The typical 
observation under these conditions is twofold. First, a peculiar 
twitching contraction of the base of the mucous gland tends to 
straighten out the angle or elbow of this gland (pl. 1, fig. E), and 
often, by forcing the contents toward the distal end, bursts this 
through and releases the mucus in the abdominal cavity. Second 
the yellow spermatic fluid can be seen passing through the trans- 
parent vas deferens, base of the mucous gland, and down the 
ejaculatory duct to the penis. Mucus and sperm are thus 
separated, and microscopical examination of the organs killed 
immediately in this condition (pl. 3, fig. 10) shows that in the 
base of the gland the mouth of the vas deferens has been forced 
against the blind end of the ejaculatory duct. Generally the 
