THE DISEASES OF CATTLE. 291 



According to concurrent testimony, the presence of biliary 

 calculi, in the gall bladder of an ox, does not interfere much 

 with the general health ; but they occasion a jaundiced appear- 

 ance, a general eye-sore, which renders yellow beef unac- 

 ceptable to the palate of an epicure, and the shrewd butcher 

 declines to deal in any thing yellow, except pure dust. 



I know of no symptoms by which the presence of biliary 

 calculi can be detected prior to death. 



The two following paragraphs occur in " Youatt on Cattle/* 

 and may throw some light on the subject : — 



" Sometimes, they [calculi] enter the duct (the cyst) which 

 conveys the bile to the intestines. They are likely to do this 

 on account of their swimming on the surface of the fluid which 

 the bladder contains. The cystic duct is large at its union 

 with the bladder ; it is a continuation of the neck of the blad- 

 der, and the gall-stone may be easily pressed into the com- 

 mencement of the tube ; but it has scarcely entered it before its 

 passage is obstructed by the folds of the inner coat of the duct. 

 These assume a semilunar form, with the edges projecting 

 towards the bladder, and they act as partial valves, retarding 

 tlie progress of the bile, so that it may not all be pressed out 

 at once, but gradually escape as the process of digestion may 

 require. 



" The gall-stone being thus impacted, violent spasmodic 

 action takes place in the muscles of the duct, occasioned by the 

 irritation of its continued pressure. It is fortunate, how- 

 ever, that, although the muscles of these ducts act with some 

 power, the obstruction is usually, with no great difficulty, over- 

 come. The duct distends ; as it distends these valvular folds 

 lie closer to the sides, and no longer oppose the passage of the 

 calculus, which is pressed on until ij; reaches the common 

 duct The calibre of this tube is larger, and, unless the cal- 

 culus is of considerable bulk, no farther difficulty occurs until 

 it reaches the opening into the duodenum, which being sit- 

 uated in the centre of a muscular prominence, acting as a 

 valve, and preventing the passage of all matters, whether 

 fluid or solid, from the intestine into the ducts, a new dif- 



