Hie Rot in Sheep. 



79 



Should a similar attempt to escape from the body of the dying 

 animal be made by flukes, a search for them in the intestinal 

 canal will prove successful. That their number, however, is 

 mostly very large within the biliary ducts, we have daily proof, 

 hundreds being often present. It is said that Leeuwenhoeck 

 took no less than " 870 out of one liver, exclusive of those that 

 were cut to pieces or destroyed in opening the various ducts."* 



Tracing the smaller ducts onwards, exit is given to a dark- 

 brown and thickish fluid, among which are masses varying in 

 size from the head of a pin to a pea, or occasionally larger ; these 

 are collections of the ova of the distomata held together by the 

 mucus of the ducts and inspissated bile. A drop of the fluid, 

 or a minute portion of one of these masses, placed under the 

 microscope, reveals the fact that in the small ducts, especially, 

 the ova are to be met with in countless myriads. We obtain 

 evidence also of another very instructive fact, to which attention 

 has been previously directed — namely, that by simply putting 

 a little of the matter upon the edge of a plate or slip of glass, 

 and lightly pressing it with the point of a scalpel, we feel the 

 ova as so much gritty matter, and we hear them cracking under 

 the pressure of the knife. Doubtless this depends on the hard- 

 ness of their shells, a property which enables them to resist de- 

 composition, and to preserve the vitality for an unknown, but long 

 period of their contained embryos when out ot the body of the 

 sheep. 



The gall-bladder itself is not much altered in structure, nor 

 does it in general contain many distomata ; but the bile within 

 it is mixed with a considerable quantity of mucus, and its colour 

 is altered from that of the greenish-yellow which normally belongs 

 to it to a blackish hue. Ova are also met with here, but in scanty 

 quantities compared with the number in the biliary ducts. 



The morbid states of the liver which we have attempted to 

 describe are, without doubt, chiefly due to the presence of the 

 entozoa within the biliary ducts. Kuchenmeister has correctly 

 observed, that " the first consequences of the flukes in the liver 

 are dilatation and catarrh of the gall-ducts, and destruction, by 

 pressure, of large portions of the parenchyma of the liver in 

 the vicinity of the enlarged ducts." No kind of food or location, 

 however prejudicial, could possibly per se produce such struc- 

 tural changes in the liver as characterise rot ; but it can be easily 

 understood that an organ like this, whose office at one and the 

 same time is to depurate the blood by its excretory function, 

 and to assist in the assimilation of the food by its secretory 

 function, being so extensively diseased, must ultimately cause 



* Yoimtt on Sheep, p. 449. 



