38 LICE AND THEIR MENACE TO MAN 



without food (Warburton). While they remain 

 active the distances that they are able to travel 

 are somewhat surprising, their movements though 

 slow being fairly persistent. A well-fed female 

 louse was observed to walk along a stretched 

 thread of cotton for a distance of four feet in 

 thirty minutes in a warm room, the impulse to 

 walk being given by placing it on the end of the 

 thread near the window. Peacock observed two 

 travel a distance of five feet in an hour where 

 they had apparently no particular stimulus to 

 guide them. By such wanderings the louse is 

 no more likely to find a fresh host than by 

 remaining where it happens to fall. If it is on 

 a smooth surface, such as a board, and a cloth 

 surface brushes over it, it immediately attaches 

 itself to the cloth. The author has occasionally 

 made use of this habit when lice have accidentally 

 fallen on the laboratory floor by passing a Turkish 

 towel over the place where they fell and at once 

 recovering them. Again, if the insect is on a cold 

 cloth surface and a warmer one is pressed against 

 it, it will immediately leave the former for the 

 latter. In this way lice may be picked up in 

 public conveyances with cushioned seats. As 

 these chances do not happen very often it is 

 certain that the vast majority of stray lice die 

 without finding a new host. The more con- 

 gested the community the more likely are they 

 to be picked up. It also follows that when lice 

 are on a discarded garment the best chance for 



