THe Hoc LousE 647 
have gorged themselves and have been seen to turn pink within a few 
minutes, owing to the rupture of the stomach and the spread of blood 
through the colon. This phenomenon, which has been invariably followed 
by death, has been seen also by Nuttall (1917 d:173) in the pediculi 
infesting man. The unfed louse is of a grayish color and much wrinkled, 
while the fed louse has a highly refractive, smooth tegument showing 
very clearly the areas of stronger chitinization. During keeping and 
rearing, immature lice have been given four, and adult lice three, oppor- 
tunities for feeding in twenty-four hours, and these were not always 
taken advantage of. Temperature influences the rate of digestion, and 
the higher the temperature in which lice are kept, the more frequent must 
be the opportunities given them for feeding. 
Sexual maturity is attained on the third day after the final molt, when, 
with or without fecundation, egg-laying begins. The position for copu- 
lation has been observed a number of times. While a female was feeding 
and still had the abdomen somewhat elevated, the male crawled under- 
neath and interlocked his first and second pairs of legs with the second 
and third pairs of the female. She at once raised her abdomen, resting 
only on the head and the first pair of legs and bearing the whole weight 
of the male. The abdomens of both were curved dorsad and the male 
was seen to insert the parameres (dilator of Nuttall) into the sexual 
orifice of the female. Gradually the bodies were lowered until the third 
pair of legs of the male rested on the arm, and the head was under that 
of the female. They remained in this position for almost ten minutes, 
during which time the male constantly stroked the head of the female 
with his antennae. In its main features this resembles copulation in the 
pediculi infesting man as described by several workers, the most detailed 
account being that of Nuttall (1917 a:316). Hog lice in captivity have 
jnot been seen to remain in copulation longer than from ten to fifteen 
/minutes, while the species infesting man crawl into hiding and remain so 
for several hours. 
The eggs (Plate LVIII, 2) are laid, one at a time, on the bristles of the 
20g and are attached to them bya clear cement. They are most abundant 
n the lower parts of the body. The egg-laying process has been watched 
m the human arm during feeding. After drawing blood for almost ten 
minutes, the female withdrew the mouth parts but remained stationary, 
olding the end of the abdomen bent downward in an unusual manner. 
wa 
