398 LICE 



and his fellow workers have shown that lice which are fed on in- 

 fected patients do not become infective until the eighth and usu- 

 ally the ninth or tenth day afterward. The same results were 

 obtained both in experiments with crushed lice and with the 

 excrement of the lice. 



Typhus is a disease which has a tendency to remain in a mild 

 epidemic state in many parts of Europe and North America, 

 ready to burst into flame when opportunity comes, giving rise to 

 terrible epidemics. Epidemics usually occur in winter and in 

 cold countries, due to the huddling together of people in warm, 

 poorly ventilated houses where lice thrive, and where the un- 

 hygienic conditions lower the vitality of the people. Typhus 

 has followed in the wake of nearly every army which has ever 

 been assembled. During the present great European war typhus 

 has been largely absent from the armies and population of 

 Britain, France and Germany, due solely to the intensive anti- 

 louse measures which have been enforced by these countries. 

 The less scientific and less cleanly nations have suffered enormous 

 losses. An epidemic began in Serbia in January, 1915, among 

 some Austrian prisoners who were allowed to disperse all over 

 the country. The disease spread with them, and for a time raged 

 almost at will in that war-stricken country. The majority of 

 the small number of Serbian doctors were affected, no sanitary 

 measures for the suppression of lice were understood or enforced, 

 and no adequate accommodations for the sick could be provided. 

 The epidemic continued to rise, and reached its height in April, 

 when there were estimated to be 9000 deaths per day. It was 

 largely through the heroic efforts of the American Red Cross 

 expedition that the epidemic was finally checked, after having 

 destroyed over 150,000 people. In December, 1916, another 

 epidemic was reported to be raging in Syria with over 1000 deaths 

 per day. Milder epidemics have occurred in Austria, Bulgaria 

 and Russia, all countries where science and cleanliness have 

 not been worshipped as they have in the greater nations of 

 Europe. Mexico has suffered also; in December, 1915, 11,000 

 cases of typhus were reported in Mexico City and its environs. 

 The disease is endemic and quite prevalent at all times on the 

 high plateaus of -Central Mexico, where it is known as " tabar- 

 dillo." Among the American troops along the border and in 

 Mexico, however, no typhus exists, due to the constant and in- 



