NOTES ON PEDICULUS VESTIMENTI. 277 



Second Is biting followed by itching? 



Third Is there evidence that Du R.'s skin is abnormally thick? 



Daily Record of the Experiment. 



September 10: 33 lice were fed on the arm between the wrist 

 and elbow. The lice varied in age, the older were between the 

 second and third moult, and the younger before the first moult. 



Behavior while Feeding. All but one fed normally, showing 

 no effort to escape, though they were slow in commencing to bite. 

 The one that refused to bite Du R. was fed on a normal host 

 four hours later and bit at once. 



September n : Three dead (all J 1 <^). Added 3 just hatched 

 (total 33). 



Behavior while Feeding. The 3 just hatched bit at once and 

 fed normally. One of the older lot did not bite, for the digestive 

 tube was ruptured. It was killed and dissected (a $). The re- 

 maining 29 fed normally. 



September 12: Four dead. Three of the four died while 

 moulting (3 $$ and I ?). 



Behavior while Feeding. One of the three that were hatched 

 September n took scarcely any blood, the other two did not bite 

 for fifteen minutes and then fed normally. One of the older lot 

 did not bite, having moulted abnormally. The balance fed nor- 

 mally. The one that could not bite was killed and dissected 

 (a?). 



September 13: Two dead (both grf). 



Behavior while Feeding. One of the 3 that were hatched 

 September n did not bite and died a few hours later (a JV). 

 One of the older lot did not bite; it was therefore killed (a $). 



The balance fed normally. 



September 14: Three dead one while moulting and one imme- 

 diately after the second moult (2 <$ and i $). 



Behavior while Feeding. One of the 2 hatched September II 

 took very little blood and the other died on Du R.'s arm (a $). 



The balance fed normally. 



September 15: One dead. Died while moulting (a <^). 



Behavior while Feeding. All fed normally. 



September 16: Three dead before the second moult (i <$ and 



