320 JOURNAL OP ECONOMIC ENTOMOLOGY [Vol. 2 



Agricultural Experiment Station combined for sixty-seven years; or 

 it would nearly support the entire educational system of the state for 

 one year. 



I have already referred to the relation between the fever tick and 

 Texas fever in cattle in the United States. On the east coast of Africa 

 a similar highlj^ fatal disease, known as African Coast fever or Rho- 

 desian fever, affecting cattle, is carried by a different species of tick. 

 Other tick-borne diseases are heartwater in sheep and cattle ; malig- 

 nant jaundice in dogs, and spirillosis in. fowls. Amongst biting insects 

 the Tsetse flies have long been known to slay the horses of African 

 travelers, and we now know that this same genus of flies is responsible 

 for the mysterious and fatal sleeping sickness that has decimated the 

 population in west and central Africa. In Busoga alone 30,000 

 natives have died in the space of three years from this cause. These 

 flies carry from inoculated to healthy persons certain parasitic pro- 

 tozoans, called trypanosomes, which live in the blood and spinal fluid 

 of man and animals. Recent investigations have shown that croco- 

 diles are intermediate hosts for the protozoans, and if these animals 

 were destroyed it is believed that sleeping sickness would cease. The 

 disease known as anthrax or black-leg in cattle has been comnumi- 

 cated to man by bites of horse flies and the common stable fly, and 

 there is little or no doubt that this disease is carried from sick to 

 healthy animals by these insects Circumstantial evidence leaves 

 scarcely a doubt that fleas carry the bubonic plague, not only from 

 person to person, but between rats and men. At the time of a bad 

 outbreak of the plague at Sidney, Australia, it is recorded that rat 

 fleas became so numerous on the wharf at Sidney that the laborers had 

 to tie string around the bottom of their trousers to protect themselves 

 from the vermin. British troops at Hong Kong, only provided with 

 boots, were much bitten by fleas and many contracted plague. The 

 British troops in India, walking in "putties." do not contract it be- 

 cause the fleas cannot get at their ankles. "Within recent years 

 mosc[uitoes have been proved to act as carriers of malaria and yellow 

 fever. By waging war against the various species of Anopheles which 

 act as malaria carriers the number of eases in Ismalia on the Suez 

 Canal, where the number of cases of fever have always been between 

 1.500 to 2.000 per annum, was reduced in one year to 209. When 

 work was begun on the Panama Canal the region through which it was 

 to be constnicted was excessively dangerous to human life. Init today 

 the workmen can sit on their outside porches in the evening without 

 being sheltered behind gauze netting, so effectually have the mosquitoes 

 been exterminated. The extent of malarial infection in some regions 



