Roi. 365 



proceeds, the liver becomes disorganized, and its secretion 

 more vitiated, and even poisonous ; and then follows a total 

 derangement of the digestive powers. 



The liver attracts the principal attention of the examiner ; 

 it displays the evident effects of acute and destructive in- 

 flammation 5 and still more plainly the ravages 6f the para- 

 sites with which its ducts are crowded. Here is plainly the 

 original seat of the disease ; the centre whence a destruc- 

 tive influence spreads on every side. Whatever else is found, 

 it is the consequence of previous mischief existing here. 

 Then the first inquiry is a very limited one — the nature of 

 this hepatic affection, and the agency of the parasites that 

 inhabit the liver. Are they the cause or consequence of dis- 

 ease ? 



The Fluke — th% Fasciola of Linnaeus — ^the Distoma he- 

 paticum of Rodolphi — is found in the biliary ducts of the 

 sheep, the goat, the deer, the ox, the horse, the ass, the hog, 

 the dog, the rabbit, and various other animals, and even in 

 the human being. It is from three-quarters of an inch to 

 an inch and a quarter in length, and from one-third to half 

 an inch in greatest breadth. The head is of a pointed form, 

 round above, and flat beneath ; and the mouth opens late- 

 rally instead of vertically. There are no barbs or tenacula, 

 as described by some authors. The eyes are placed on the 

 most prominent part of the head. No difference of sex has 

 yet been discovered in the fluke-worm, and it is believed 

 to be an hermaphrodite. ' * * * * 



Then, is the fluke-worm the cause or the effect of the 

 rot 1 To a certain degree both. They aggravate the dis- 

 ease ; they perpetuate a state of irritability and disorgani- 

 zation, which must necessarily undermine the strength of 

 any animal ; they unnaturally distend, and consequently 

 weaken the passages in which they are f^und ; they force 

 themselves into the smaller passages, and, always swimming 

 against the stream, they obstruct the flow .of the bile, and 

 produce inflammation by its accumulation ; they consume 

 the nutritive juices by which the neighboring parts should 

 be fed ; and they impede the flow of the bile into the intes- 

 tines, by clogging up the ducts with their excrement and 

 their spawn. Notwithstanding all th\s, however, if the 

 fluke follows the analogy of other entozoa and parasites, it 

 is the efiect and not the cause of the rot. The ova are 

 continually swallowed by the sound animals and the dis- 



31* 



