l88 SOME SOUTH INDIAN INSECTS. ETC. CHAR XX. 



Enteric Fever is a term generally used to include Typhoid Fever 

 and two Paratyphoid Fevers. It is commonly carried by House-flies 

 and sometimes also bj Drosophila, a small fly which is equally 

 at home on excrement and on ripe fruit. Enteric fever may of 

 course be carried by milk, water, ice, fish, etc., which easily become 

 contaminated directly, but the agency of flies in carrying germs 

 on their feet or in their intestines, from infected excrement on to 

 food (especially milk) is usually much under-rated. In this connec- 

 tion it is noteworthy that Europeans are most liable to enteric in 

 the dry season when the infection is carried on to food by dust and 

 flies, and Natives in the monsoon owing to the pollution of water- 

 supplies by surface drainage. 



Filariasis, in its commonest form of Elephantiasis, is caused 

 b) a minute Nemathelminth worm. Filaria bancrofti, which is carried 

 by various mosquitos (e.g., Culex fatigans, Mansonia uniformis, and 

 the Anophelines marked in the list on page l8l), and which 

 when in numbers blocks the lymphatic vessels of the body. 



Leprosy is perhaps insect-borne although the exact means of 

 transmission is as yet unknown. 



Yaws or Framboesia tropica, caused bj Treponema pertenue, is 

 very common in Ceylon but apparently rarer in India. It is probably 

 carried by flies sucking the open sores of patients and carrying the 

 infective organisms to ordinary ulcers or sores which are thereby 

 infected. 



Epidemic Dropsy has occurred in Southern India as an epi- 

 demic, especially in [876 77 when there was a great famine. The 

 exact cause is unknown but it is suspected to be an organism 



, I by bed-bugs. 



Cholera is usuallj carried by water, milk, fruit, etc., which maj 

 be contaminated directly by flies which have previously visited the 

 discharges oi 1 holera patients. 



Dysenteries, caused by various organisms, are also due to 

 infection oi the intestinal tract with drinking-water, milk, green 

 vegetables, etc., which have been contaminated either directly 

 or by means of flies or similar insects. 



Guinea-Worm is the infection oi man with Dracunculus medi- 

 nensis, a Nemathelminth worm which passes the first portion of 

 its life-cycle in the body of Cyclops, a minute crustacean which 

 is commonly called a "water-flea." It an infected Cyclops is 

 swallowed with drinking-water it is killed in the stomach but 

 the contained worm is liberated and makes its way into the 

 tissues of its new host. The individuals "l Cyclops mostly live 

 near the bottoms of wells and pools and are therefore most 



