514 Dr. H. B. Fantham. Herpetomonas pediculi, n. sp., [Nov. 24, 



The eggs of P. vestimenti vary in their incubation period. I found that 

 while a few eggs hatched in four to five days, others matured as much as 

 six weeks after laying. Warburton found the same kind of variation. 

 The larvae were pale coloured, and fed as soon as they left the egg, if placed 

 on the back of the hand. Moulting occurred every four days, the new 

 skins being slightly darker than the previous ones. The larvae fed very 

 greedily, and were much more active than the adults. When feeding, a 

 larva has sucked blood for as long as 25 minutes, peristaltic waves being 

 clearly visible in the gut the while. Usually 10 to 15 minutes' feed was 

 sufficient. 



The imaginal stage is attained about eleven to twelve days after hatching, 

 sexual maturity about four days later. Copulation is intermittent, but 

 frequent. In several cases it occurred shortly after feeding, particularly 

 when the insects fed greedily, so that unchanged fresh blood occasionally 

 passed from their bodies after the semi-solid digested blood oUbris had 

 ceased to be voided. Egg laying at the rate of four or five per day occurs 

 during the rest of the life of the female, who is longer-lived than the male. 

 Warburton found that the adult life of a male was about three weeks, that 

 of a female four weeks. In my own experiments similar results were 

 obtained, but I also found that the length of life was sometimes about a 

 week less, in each sex. 



The mode of feeding of adult P. vestimenti is of interest. After settling 

 down on the hand, often clinging to the scrap of cloth on which they usually 

 rest, a fairly sharp stab is made, and immediately the blood begins to flow 

 into the alimentary canal, which becomes bright red. As feeding proceeds, 

 the louse gradually raises its abdomen, until it is almost vertical in extreme 

 cases. As fresh blood passes into the gut, defaecation occurs, much 

 excrement being produced. If an attempt be made to remove a louse before 

 it has finished its feed, the pull of the ring of hooks near the lower lip can 

 be felt. Lice fed in a somewhat restricted area showed no hesitation in 

 sucking blood at spots fouled by themselves or their neighbours. Adult 

 lice would feed for 20 to 30 minutes. If feeding were neglected, the lice 

 died in about three days. I found it necessary to feed them at least twice 

 daily, though I have succeeded in keeping two females alive for three weeks 

 when fed only once a day. Larvae perish if not fed within 36 hours of 

 hatching, and even then there is great loss during the larval stage. 



Lice are also very sensitive to changes of temperature. Body heat 

 seems necessary for them, though eggs can withstand great extremes of 

 temperature. 



Death of P. vestimenti appears to occur very suddenly. I found that a 



