350 ENTOZOA. 



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of days are required for their arrival ia the muscles, and that new 

 ones are not produced after six or seven weeks, it will be under- 

 stood that the first symptoms of this stage can scarcely appear' 

 until the end of a fortnight after ingestion of the diseased food, 

 that they must continue four or five weeks, an'd that after this 

 they may disappear. This course of events is observed in animals ; 

 and in man, the symptoms of this stage have sliown themselves and 

 become aggravated from the third to the sixth week after infection. 

 Most animals die during this stage ; rabbits rarely survive ; rats, 

 on the contrary, generally resist it. 



" If the animals do not die of the general symptoms or local 

 disturbances proper to these two stages, the inflammatory symp- 

 toms cease, respiration becomes natural, and order is re-established. 

 But, in some cases, the number of cysts formed in the muscles are 

 sufficiently great to impede them in the proper exercise of their 

 functions, and hence arises general debility, a kind of consumption 

 which persists or becomes aggravated, and the animal . dies of 

 marasmus. M. Davaine has noticed this in rabbits, but especially 

 in a rat. 



" Recovery from these phases of trichinal infection may be 

 apparently perfect. A rabbit, which M. Davaine kept during five 

 months, became large and fat, although it had a large number of 

 Trichinse in its muscles ; a rat which had had these Bntozoa in con- 

 siderable numbers during six months, was, to all appearance, in 

 good health. Hence he concludes that the Trichinae produce symp- 

 toms only when they are in the intes'tinal canal, and when they are 

 entering the muscles. Having become lodged in their cysts among 

 the muscular fibres, they may remain harmless for an indefinite 

 time. In every case except one, down to 1859, Trichina have been 

 found in the bodies of persons who have died of disease (generally 

 chronic) or by accident; or in the dissecting-room, in bodies 

 regarding which the previous history could not be obtained. In 

 most cases, the cysts contained a cretaceous or fatty deposit, 

 showing that they had probably existed several years. 



