THE HOUSE FLY 47 



over, the number of deaths from malaria in Habana was greatly re- 

 duced from 325 in 1900 to 151 in 1901, 77 in 1902, and 45 up to the 

 first of November, 1903. 



In 1905, yellow fever broke out in New Orleans. The situation was 

 critical, and on August 12 was placed under the control of the Public 

 Health and Marine-Hospital Service under Dr. White. A warfare 

 against the yellow-fever mosquito was at once commenced. This mos- 

 quito was found breeding in the rain-water cisterns which abounded in 

 the city. These cisterns were screened, and various pools treated. The 

 epidemic abated at once, and the total number of deaths was 460 as 

 against 4,046 in the epidemic of 1878, 4,858 in 1858, and 7,848 in 1853. 



Similar control measures have been inaugurated in the Panama 

 Canal zone, with the result that the canal is soon to be completed and 

 the region is now considered fairly salubrious, though the French had 

 to abandon their work there on account of the unhealthy climate. 



Measures for Controlling Mosquitoes 

 Mosquito prophylaxis is usually an engineering problem pure and 

 simple — abolish breeding places. This can be done in nine out of ten 

 cases by filling and draining at small expense. In the tenth case it may 

 be advisable, on account of expense, to make a permanent pool and 

 stock it with carnivorous fishes. The edges should be deep and abrupt, 

 and kept clean and free from vegetation. In the salt marshes, ditches 

 should be opened so that the tide may ebb and flow through them, and 

 mosquitoes will not breed there. Fill all small depressions. 



Screen all houses, and also screen all cisterns and rain-water barrels 

 to keep mosquitoes out of them. Treat the surface of all breeding 

 places once each ten days with oil to prevent the breeding of mosquitoes 

 therein until these pools can be made permanently safe. 



Fleas and Plague 

 Bubonic plague, or " black death," has always been one of the most 

 dreaded diseases of mankind, and from the scourge of Egypt, beginning 

 about a.d. 542 and lasting sixty years, down to the San Francisco epi- 

 demic of 1907-08, communities and government authorities have been 

 powerless to cope with it. In India even at present, according to the 

 newspapers, the mortality from this disease was 43,508 for the month of 

 February and 95,884 for March, 1911. As it has always been serious 

 in India, various commissions there and in other countries have each 

 investigated and made their own contributions toward a knowledge of 

 the disease. From 1896 to 1903, during these investigations, it was 

 learned that the bacterial germ Bacillus pestis, causing the disease, 

 entered through some wound, puncture or abrasion of the skin, and 

 that all fleas and bugs sucking the blood of dying plague-diseased ani- 



