94 PEACTICAL PAEASITOLOGY 



Ascaris mystax (now called A. canis) and Tcenia elliptica (Dipylidium 

 caninum). Other varieties, though comparatively frequent, are by 

 no means invariable; such is T. crassicollis. Others again, such as 

 Bothriocephalus felis, Opisthorchis felineus (v. Linstow calls it Dis- 

 tomum lanceolatum) , are comparatively rare ; while certain imported 

 varieties, as Oxyuris compar, may be occasionally met with. There 

 are also a small number of quite rare species, and others again which 

 are rare in the cat, though encountered frequently in other hosts. 



The animal should be chloroformed, and examined as soon as 

 possible after death. 1 It is laid upon its back and fastened securely 

 by the legs, which should be turned outwards. The neck should be 

 drawn back, the head fixed, and the skin freed from any ectoparasites 

 (fleas, lice, ticks) which may be present. An incision is now made in 

 the skin down the entire length of the body, beginning at the chin and 

 ending at the anus. The skin is rapidly freed from the sides, the 

 rib-cartilages are severed, and the breast-bone removed. The peri- 

 toneal cavity is] opened up by means of a long incision through the 

 thin muscular wall of the abdomen. As Cysticercus elongatus, 

 Blbrg., is occasionally found in both the peritoneal and the pleural 

 cavities; this should be first sought for, the viscera being raised in 

 such a way as to leave the cavities free to inspection. The lungs 

 should next be examined, and here a roundworm, Strongylus nanus, 

 A. Mull., which varies in length from 5 mm. to 10 mm., may be 

 found. Its presence is betrayed by the condition of the lung, and may 

 be verified by microscopic examination of the bronchial mucus, oval 

 eggs in all stages of development and free embryos being found. In 

 such a case, the bronchi should be opened down to the smallest 

 branches, and the worms removed from the lung-tissue. 2 The bowel 

 should next be examined. After removing the omentum, the small 

 intestine should be cut across immediately behind the stomach. The 

 cut end should be held with the left hand (or by means of tweezers), 

 and the mesentery separated with a scalpel from the whole of the 

 small intestine, as far as the commencement of the colon. The 

 small intestine is next cut across at the caecum ; it is laid upon a 



1 Wherever possible, Helminthes should be sought in the freshly killed cadaver, 

 as many species do not long survive the death of their host. The decomposition of 

 Helminthes follows very quickly after death. The Taeniee of birds, for instance, 

 possess but slight power of resistance. Nematodes, on the other hand, are com- 

 paratively robust, as are the encysted forms of the greater number of Helminthes. 

 The latter are frequently found alive in organs which are already in a state of 

 maceration. 



2 In North America, Paragonimus westermani is found in the lung of cats. This 

 parasite may occur in man, but its normal host is the tiger. It occurs also in swine 

 and dogs, but only when their habitat is extra-European. 



