PARASITES OF ANIMALS. 115 



In some very severe cases the numbers contained in human 

 bodies have been estimated, by reliable authorities, as 

 high as forty and sixty millions. 



The cysts containing Trichince were first observed in human 

 muscles in 1822, but the worms from similar cysts were first 

 named and described by Owen, in 1835, but were only regarded 

 as anatomical curiosities of no practical importance, until 1860, 

 when Zenker proved that they are capable of producing the 

 severe and often fatal disease now well known under the name 

 of Trichiniasis, but which had been previously (as it often is 

 still) confounded with typhoid fever, inflammatory rheuma- 

 tism or rheumatic fever, poisoning, and various other 

 diseases. 



Symptoms and treatment of the disease. 



The disease caused by this parasite has three more or less 

 distinct phases : 



First. While the mature worms and young remain in the 

 intestine, and while passing through its walls. In this stage 

 the symptoms are derangement and inflammation of the in- 

 testine, often resulting in severe diarrhoea, nausea and vomit- 

 ing, swelling and pain, and sometimes peritonitis, due to the 

 perforations of the intestinal walls. These symptoms ensue 

 in two or three days after swallowing the trichinous flesh, and 

 may last a fortnight or more. Animals experimented upon often 

 die in this stage. Purgatives and anthelmintics are used in 

 this stage to expel the mature and pregnant females, but after 

 three or four weeks have passed this will be useless. Castor- 

 oil and calomel have been used with success for this purpose. 



Second. While the young worms are migrating and work- 

 ing in the muscles, a variety of symptoms are developed, 

 varying in different persons, and depending, also, upon the 

 number of worms. This stage commences in ten to fourteen 

 days, and generally lasts four or five weeks. The principal 

 symptoms are lassitude and swelling of the muscles, with 

 soreness, or intolerable pains, resembling rheumatic pains but 

 not affecting the joints ; profuse sweating sometimes occurs ; 

 the pulse is very rapid, but the heat of the body is usually 



