Gr. H. F. Nuttall 
401 
(b) When fed. 
Of the two specimens I raised experimentally, the male lived 22 days, 
and the female 17 days, as adults. The insects will doubtless live longer. 
Feeding Habits. 
When a newly emerged larva is placed upon a hair, close to its base, 
it immediately punctures the skin and proceeds to feed. It differs in 
its feeding habits from Pediculus, for it remains for days upon the same 
Fig. 9. Phthirus pubis, larvae of the first stage. A-D grasping a single hair, E, F, G, 
grasping two hairs; all of them drawn from life in the act of feeding. H, ventral 
aspect of larva killed by immersion m alcohol and mounted in balsam; it shows the 
manner of grasping a hair. A and B represent the same larva when respectively 
one and two days old, C another larva three days old, E and G others four days old, 
D is one day old, and F two days old grasping crossed hairs. G shows how a hair, 
whose root is at some distance, is bent by the insect’s grasp. E shows the usual 
position in aU stages when grasping two hairs. The arched dotted line indicates the 
border of the hair-pit in some instances. 
spot without appearing to withdraw its mouthparts, whilst a micro¬ 
scopic examination shows that it pumps blood intermittently at frequent 
intervals. On one occasion only did I find an insect with its mouthparts 
■withdrawn, but they were soon reintroduced. During the first day, or 
for two or more days, the young larva as a rule grasps but a single hair 
with its four strong posterior legs (see Fig. 9), whilst its body gradually 
