PARASITES. 6 1 



in the muscle, The latter can only reach maturity and repro- 

 duce their kind when the animal which they infest is devoured 

 by another, and they are set free by the digestion of their 

 cysts. When thus introduced into the bowels they grow and 



Fig. lo — Muscle Trichina encysted, magnified. 



propagate their kind, giving rise to much irritation for the first 

 fortnight, diarrhoea, enteritis, or peritonitis. The symptoms 

 caused by their boring through the bowels and into the muscles 

 last Irom the eighth to the fiftieth day. There are violent 

 muscular pains like rheumatism, but not affecting the joints, a 

 stiff, semiflexed condition of the limbs, and sometimes swellings 

 on the skin. In man the affection is often mistaken for rheu- 

 matism or typhoid fever, in the lower animals the symptoms 

 are usually less marked, but are the same in kind. There are 

 loss of appetite, indisposition to move, pain when handled, and 

 stiffness behind. If the patient survives six weeks recovery 

 may be expected, because the worms no longer irritate after 

 becoming encysted in the muscle. 



Treatment. — In the first six weeks, but especially for the first 

 fortnight, use laxatives and vermifuges. Glycerine, benzine, 

 Duppel's animal oil, chloroform, alcohol, and picric acid are 

 fatal to them in about the order named. 



Prevoition. — Never eat underdone meat. Trichina survive 

 140^ F. Hams thoroughly smoked are safe. Slightly-smoked 

 hams and those steeped in creosote or carbolic acid are most 

 dangerous. Pigs should not be kept near slaughter-houses, 



