INSECTS AND WAR 9 



who used to oil their long locks before going into 

 battle, may have feared this parasite. Some 

 German soldiers, before going to war, shave 

 their heads ; thus they afford no nidus for P. 

 capitis. The wigs worn in the late seventeenth 

 and at the beginning of the eighteenth centuries 

 undoubtedly owed something to the difficulty of 

 keeping this particular kind of vermin down. 

 The later powdering of the hair may have been 

 due to the same cause. 



P. capitis is in war-time less important than 

 P. vestimenti. The former certainly causes a 

 certain skin trouble, but the latter not only 

 affords constant irritation, but, like most biting 

 insects, from time to time conveys most serious 

 diseases. P. vestimenti is known to be the carrier 

 of typhus. This was, I believe, first demon- 

 strated in Algeria, but was amply confirmed 

 two years ago in Ireland, when a serious outbreak 

 of this fever took place, though little was heard of 

 it in England. Possibly, P. capitis also conveys 

 typhus, but undoubtedly both convey Spiro- 

 chaeta recurrentis the cause of relapsing or recur- 

 rent fever. 



The irritation due to the body-louse weakens 

 the host and prevents sleep; besides there 



