122 INFECTIOUS AND PARASITIC DISEASES. 



eggs are quite characteristic and easily recognized. 

 The hving worm is seldom found in the stools. 

 Strongy- Occurs in the stools in endemic diarrhoea 

 LoiDEs of hot countries (Cochin-China). Has also 



Intestin- been described in this country by Thayer. 

 ALis. Infestment only produces symptoms when 



the parasites are present in large numbers. Eggs of 

 the parasites are probably ingested with drinking-water. 

 Trichiniasis, as infestment of the body 

 Trichinella with the trichinella spiralis is 

 Spiralis called, is brought about by eat- 

 (Trichina ing insufficiently cooked or raw 

 spiralis). meat (usually pork) which con- 



tains the larval forms. The 

 young embryos which are set free in the 

 stomach by digestion of their capsules, reach g _ . 

 maturity in the small intestines in about chiuHs trichi- 

 three days. The females then give birth size': .4, male; 

 to innumerable larvae — 8,000 to 10,000, it is %ll^\^ ^' 

 said — which are discharged directly into the 

 lymph stream, whence they finally reach the blood and 

 are distributed to their points of election, the voluntary 

 muscles. Here the young worms become encysted, 

 i.e., each one arranges itself in a spiral, and becomes 

 surrounded by an inflammatory capsule. It is to the 

 encapsulation of the embryos, together with a poison 

 which is possibly set free by them, that the symptoms 

 of trichiniasis are due. 



