400 LICE 



jecting them with ground bodies of head lice taken from plague 

 patients. The practice among some natives of killing lice by 

 mashing them against the head of the host, accompanied by the 

 frequent scratching due to irritation from bites, may well be a 

 frequent cause of plague infection if there has been any oppor- 

 tunity for the lice to migrate from an infected to a healthy person. 



There is no reason why syphilis could not be transmitted in 

 a similar manner, especially during the second stage of the dis- 

 ease, when the spirochaetes are present throughout the blood. 

 The readiness with which spirochaetes of other kinds will live in 

 insect or tick bodies makes it reasonable to believe that the 

 spirochetes of syphilis might live in the bodies of human lice, 

 at least long enough to be conveyed from person to person. 



Prevention and Remedies. — The prevention of lousiness con- 

 sists primarily in personal cleanliness. However, no amount 

 of personal hygiene and cleanliness will prevent temporary 

 lousiness if there is association with unclean and careless com- 

 panions. Lousiness and human wretchedness and degradation 

 have always been companions, but this does not imply that lice 

 have any inherent abhorrence of a clean body if they can get 

 access to it. From the nature of their habitats the common 

 modes of infection of the three different species of human lice 

 vary somewhat. Any of them will spread by contact or close 

 association, but each has its own special means of finding new 

 hosts. The head louse depends largely for distribution on a 

 promiscuous use of combs and brushes or borrowed hats and 

 caps, and on the free-for-all trying on of head gear in haberdash- 

 eries and millinery shops. The body louse is dispersed by cloth- 

 ing and bed linen and finds fresh hunting grounds by night 

 migrations from one pile of clothes to another. The crab louse 

 frequently utilizes public toilets for dissemination. Where men 

 are crowded together in prisons or war camps lousiness is almost 

 sure to develop unless particularly guarded against, since some 

 uncleanly persons are nearly always in the aggregation, and con- 

 ditions are such that the infestation is given every opportunity 

 to spread. There are, however, many ways in which lice may 

 be dispersed among clean people in ordinary life. Stiles reports 

 a case where a large number of girls in a fashionable boarding 

 house in eastern United States developed lousiness shortly after 

 traveling from Chicago to New York in a Pullman sleeper. 



