SWINE, DISEASE OF. 



771 



hundred live trichina}, and the process is re- 

 peated twice or three times during the lifetime 



of these trichinae, a period probably of from 

 two to three weeks. It is said by careful ob- 

 servers that the female worm gives birth to 

 from two to three hundred young. The parent 

 parasites never leave the stomach and aliment- 

 ary canal. Fig. 3 represents the full-grown 

 male and female trichinae, magnified two hun- 

 dred diameters. 



Fig.Z 



1. Full-grown male trichinae. 2. Full-grown 

 female, in the act of extruding the young alive 

 magnified two hundred diameters. 



Figure 4 represents the trichinae in a free state, 

 magnified fifty diameters. 



Figure 5 represents them elaborating their 

 capsules, also magnified fifty diameters. They 



FigS 



avoid the brain, lungs, and liver, and in only a 

 single instance has one been found in the snb- 

 stance of the heart. Their perforation of the 

 stomach and bowels often gives rise to acute 

 diarrhoea and dysenteric symptoms, and where 

 they attack the serous membranes lining the 

 abdominal walls, symptoms of peritonitis are 

 added. This inflammation of the serous mem- 

 brane, if it does not prove fatal, leaves the intes- 

 tines firmly glued together. The muscles of 

 the chest and anterior portion of the neck, and 

 those of the back and extremities, are those in 

 which they seem to find their most congenial 

 resting-place. It is somewhat remarkable that 

 children suffer much less than adults from the 

 incursions of these parasites, and in their case 

 they seldom prove fatal, while among adults 

 from twenty-five to seventy-five per cent, of 

 those attacked die. The muscles upon which 

 this animal has fed become useless in propor- 

 tion to the number of ultimate fibres which are 

 destroyed. When it is remembered that a single 

 ounce of flesh may contain trichinae enough to 

 produce in eight days 3,000,000 young, it is not 

 surprising that the entire substance of the ab- 

 dominal muscles should be sometimes found 

 consumed. 



The history of the discovery of this parasite 

 is interesting as exhibiting the carefulness and 

 thoroughness of scientific research. About the 

 year 1832 several English physicians noticed in 

 lean flesh a minute yellowish white granule, 

 which is the adventitious shell enclosing the 

 worm. These Hilton, an English anatomist, 

 supposed to be animals ; but the zoologist Owen 

 was the first who described and named the 

 worm itself Trichina spiralis. This was in 

 1835. Precisely as the yolk and white of a 

 hen's egg are not visible through the shell 

 which contains them, .so with the trichinae. It 

 is frequently from one-third to one-half a line 

 long, measured when its body is uncoiled ; but, 

 from its transparency, it cannot with the naked 

 eye be recognized as having the structure of an 

 animal. This, however, can readily be seen 

 under a lens of fifty or sixty diameters. A 

 number of observers have found this animal in 

 the persons of natives of England, France, Ger- 

 many, Denmark, and North America. The 

 diseases it occasions, and the deaths owing to 

 its presence in the flesh of human beings, have 

 for years engaged the attention of the medical 

 men of Germany, and have at several periods 

 alarmed the people of that country. The epi- 

 demic of this disease which recently occurred 



