8-t 



DISEASES OF MUSCLES AND TENDONS. 



Beef measles is rather common in Germany, but rare m France, 

 Switzerland, and Italy. 



TRICHINIA.SIS-TRICHINOSIS. 



Trichinosis is a disease caused hy the entrance into the body of the 

 Trirhiiia spiralis. This parasite is swallowed in the larval form, and 

 undergoes sexual changes in the intestine, at first producing intestinal 

 trichinosis, which represents the first phase in the development of the 

 disease. 



The triuhinse breed rapidly. The embryos penetrate into or are 

 directly deposited in the blood-vessels, which convey them to all parts of 



Fig. 44. — Gravid segment of beef- 

 measle tapeworm {Ticiiin sarji- 

 nittii), showing lateral branches 

 of the uterus, enlarged. (Stiles, 

 Annual Eeport U.S.A. Bureau 

 of Agriculture, 1901.) 



Fig. 45. — Egg of beef-measle tapeworm 

 (Tcenia saijinata), with thick egg-shell 

 (embryophore), containing the six- 

 hooked embryo (oncosphere), enlarged. 

 (.After Leuckart.) 



the body, thus setting up the second phase of the disease, known as 

 muscular trichinosis. 



Trichinosis as a disease has long been recognised. Peacock in 1828 

 and J. Hilton in ls:]'2 mentioned the existence of the cysts of trichinae; 

 Owen in liS35 gave the name of Tridiina spiralis to the parasites con- 

 tained in the cysts. Trichinosis being common in Germany at that time, 

 Yircho-w and Leuckart undertook its investigation, but mistook other 

 nematodes of the intestine for the Trichina spiralis. In 1847 Leydy 

 recf)gnised that tricliinosis occurred in American pigs. 



In 18(10 Zenker found muscular and intestinal trichinosis on post- 

 mortem examination of a girl who had been suspected of suffering from 

 tyi)hoid fever, and a carefully conducted inquiry revealed the fact that 



