176 



ENTOZOA. 



of tealtli. Not only is the rigidity and firm consistency of the 

 muscles altogether wanting, but these structures have lost that 

 deep reddish colour which normally exists. When the abdominal 

 cavity is opened a more or less abundant, clear, limpid, or yellowish 

 fluid win make its escape, and the entire visceral contents will, at 

 the same time, display a remarkably blanched aspect. These 

 pathological changes are also shared by the important organ espe- 

 cially affected, namely, the Hver. This gland has lost its general 

 plumpness, smoothness, and rich, reddish-brown colour, and has 

 become irregularly knotted and uneven both at the surface and the 

 margins ; its colouring being either a dirty chocolate brown, more 

 or less strongly pronounced at different parts, or it has a peculiar 

 yellowish tint, which ia places is very pale and conspicuous. To 

 the feel it is hard and brawny, and when incised by the scalpel, 

 yields a tough and, in places, a very gritty sensation. On opening 

 the gaU-ducts a dark, thick, grumous, bihary secretion oozes slowly 

 out, together with several distomes, which, if not dead, slowly curve 

 upon themselves, and roU up like a sHp of heated parchment. On 

 further shtting open the biliary passages, they are found distended 

 irregularly at various points, and in certain, situations many flukes 

 are massed together, having caused the ducts to form large sacs, in 

 which the parasites are snugly ensconced. The walls of the ducts 

 are also much thickened in places, and hardened by a deposit of 

 coarse calcareous grains on their inner surface. Mr. Simonds says, 

 that " the coats of the ductus hepaticus, as also of the ductus com/m/w- 

 nis clioledicus, are not unfrequently so thick as to be upwards often 

 times their normal substance, and, likewise, as hard as to approach 

 the nature of cartilage." Respecting their numbers, the greatest 

 variation exists. The presence of a few flukes in the Hver is totally 

 insufficient to cause death ; consequently, when a sheep dies from 

 rot, or is killed at a time when the disease has seriously impover- 

 ished the animal, then we are sure to find the organ occupied by 

 many dozen, many score, or even several hundred flukes. Thus 

 from a single hver Bidloo obtained 800, Leuwenhoeck about 900, 



