October, '09] JOURNAL of ECONOMIC ENTOMOLOGY 321 



may be gathered from such figures as these: In 1900 deaths from 

 fever (unclassified) in India amounted to -4.919. 591. most of the cases 

 being in all probability malarial. That is, a population, greater than 

 that of the state of Ohio, was carried otf in a single year. The hos- 

 pital returns from the Indian army report that in this same year 

 the army amounted to 60.653 men, of which 19,445, or nearly one 

 third were so badly incapacitated by malaria that they were obliged 

 to quit dut}' and receive hospital treatment. The blood parasites 

 or protozoans which cause malaria reproduce in man's blood and 

 fresh generations invade the red corpuscles, causing chills. Ano- 

 pheline mosquitoes, sucking up the asexual forms of the parasite with 

 the blood, carry these in their stomachs and salivary glands until a 

 sexual generation is produced. The latter form of the parasite is in- 

 jected into the blood of the next human victim bitten. Yellow fever 

 is carried by the tiger or brindled mosquito, a sprightly, rapid-flying 

 insect, found over the southern states and as far north as Kentucky, 

 also in the West Indies, in South America, in the European countries 

 bordering the ^Mediterranean and across Asia to China. Wherever the 

 species occurs and a yellow fever patient goes there is always a chance 

 of the dread disease spreading. Ships may convey infected mosquitoes 

 long distances. This species breeds largely in barrels, cisterns, foun- 

 tains and discarded tin cans in which fruits, vegetables, fish, etc., have 

 been preserved. Anything that holds water is inviting to them. Be- 

 fore the American occupation of Cuba the deaths in Havana varied 

 during the period 1889 to 1900 from 118 to 1,355 per year. In 1901, 

 the first year in which a systematic and wholesale warfare was directed 

 against the mosquitoes, the number of deaths was reduced to five, and 

 in 1902 not a single case occurred. The disease known in tropical 

 regions as elephantiasis or Filariasis is also carried by mosquitoes. 

 This disease is caused by minute parasitic worms, which live in the 

 skin and the lymph. The skin becomes thickened like an elephant's 

 hide, hence the name of the disease. Doctor Graham of Beyrout 

 states that dengue or Dandy Fever is carried by a species of Culex. 

 There is good reason for thinking that fleas transmit leprosy, and 

 bedbugs are practically known, from circumstantial evidence, to have 

 Ijeen carriers of this disease in some cases. 



Other offices of insects are to destroy noxious plants, to act as pol- 

 lenizers of plants, to act as scavengers, to work over the soil, bringing 

 the subsoil to the surface and passing the earth through their bodies, 

 thereby enriching it with their intestinal secretions; to furnish human 

 food, to produce materials for clothing, such as silk, and to furnish 

 food for such useful animals as birds and fishes. 



