THE TRICHINA. 



l>y six tubercles. Eustrongylus papillosus Diesing, accord- 

 ing to "VVymaii, lives coiled up in the brain of the aiihinga, 

 or snake-bird of Florida. E. buteonis Packard was found 

 living under the eyes of Buteo Swainsoni, and E. chordeilis 

 Packard in the brain of the night-hawk. Doclimius duoden- 

 alis Dubini lives in the small intestine of man. 



Trichocephalus dispar Eudolphi (Fig. 86) lives in the 

 03cum of man, with the smaller anterior part of the body 

 buried in the mucous membrane. 



The most formidable round worm is the Trichina spiralis 

 Owen (Fig. 87). The body is regularly 

 cylindrical, tapering gradually from the 

 posterior end to the head. The end of the 

 body of the male is without a spiculum, but 

 with two conical terminal tubercles. It is 

 1.5 millimetres long. The female is 3 mil- 

 limetres in length. 



Viviparous females begin about eight days 

 after entering the intestine of their host to 

 give birth to the larvae, which bore through 

 the walls of the intestines of their host, 

 passing into the body-cavity, and partly in- 

 to the connective tissue, and also, by means 

 o the circulation, into the muscles. In 

 about fourteen days the worm coils up 

 spirally in a cvst (Fig. 87), which eventu- 



V, , " , & \ i , , T71 Fig. til. -Trichina 



ally becomes calcareous and whitish. When encysted m human 

 the flesh of the pig, infested by the encysted S&1S5%3 

 larvae, is eaten by man, the young worms art ' 

 are set free in the stomach of their new host, and in three 

 or four days become sexually mature. The female Trichina 

 is capable of producing a thousand young. The original 

 host of the Trichina is the rat ; dead rats are often de- 

 voured by pigs, and the use of raw or partially cooked pork 

 as food is the means of infection in man. 



Another worm, occasionally parasitic in sailors and resi- 

 dents of the East Indies, is the Filaria medinensis Gmelin, 

 or Guinea-worm. It is remarkably long and slender, some- 

 times over two foot in length. The female is viviparous, 



