viii LICE AND THEIR MENACE TO MAN 



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others, among whom may be mentioned especi- 

 ally Captain H. Orr, of the Canadian Army 

 Medical Service, and Captain J. T. Grant, 

 R.A.M.C., have devised means for reducing lice 

 in the armies. It is due, not to any fault in the 

 methods suggested, but to the excessive diffi- 

 culties of applying them under campaigning 

 conditions, that lice continue to exist among the 

 troops. Meanwhile many superstitions still sur- 

 round the insect, and an effort has been made to 

 dispel some of these. 



Since Sir Patrick Manson, Sir David Bruce, and 

 Sir Ronald Ross first showed that insects could 

 play so important a part in the spread of diseases 

 much advance in knowledge has been made, and 

 it has been shown that malady after malady is 

 conveyed by them, until to-day we know that 

 insects are responsible for a large proportion of 

 the ills from which man suffers. It would have 

 been strange if the louse, this little pest which 

 shares our clothes and lives on such intimate 

 terms with us, had not been incriminated. In 

 the space of a very few years it has been found so 

 guilty that it now ranks with the mosquitoes and 

 the rat-fleas in its malign influences. Typhus, 

 one of the most dreaded epidemic diseases of man, 

 is entirely due to its activities. The same re- 

 mark applies to relapsing fever over the greater 

 portion of the world, including Europe and Asia. 

 This knowledge we owe to Doctor Nicolle and 

 Doctor Sergent and their co-workers. The im- 



