COLIC. t>05 



same description of cells. The intention of this is evident, — to retard the 

 progress of the food, and to give a more extensive surface on which the 

 vessels of the lacteals may open : and therefore, in the colon, all the chyle 

 is finally separated and taken up. When this is nearly accomplished, the 

 construction of the colon is somewhat changed : we find but two bands 

 towards the rectum, and these not puckering the intestine so much, or forn^- 

 ing such numerous or deep cells. The food does not require to be much 

 lono*er detained, and the mechanism for detaining it is gradually disap- 

 pearing. The blood-vessels and absorbents are likewise rapidly diminish- 

 ing. The colon, also, once more contracts in size, and the chyle having 

 been all absorbed, the remaining mass, being of a harder consistence, 

 is moulded into pellets or balls in its passage through these shallower 

 cells. ^ • 



At the termination of the colon, the Rectum (straight gut) commences. 

 It is smaller in circumference and capacity than the colon, and serves as a 

 reservoir for the dung until it is evacuated. It has none of these bands, be- 

 cause, all the nutriment being extracted, the passage of the excrement that 

 remains should be hastened and not retarded. ' This descends to the lower 

 part of the rectum, which somewhat enlarges to receive it ; and w^hen it has 

 accumulated to a certain extent, the animal, by the aid of the diaphragm 

 and the muscles of the belly, presses it out, and it is evacuated. A cu- 

 rious circular muscle, and always in action, called the sphincter (binder 

 together), is placed at the anus, to prevent the constant and unpleasant 

 dropping of the fseces, and to retain them mitil the animal is disposed vo- 

 luntarily to expel them. , 



DISEASES OF THE INTESTINES* 



These form a very important pari of horse surgery, and many erroneous 

 notions are prevalent respecting them. The first disease we will consider is 



SPASMODIC COLIC. 



We have said, that the passage of the food through the intestinal canal 

 is effected by the alternate contraction and relaxation of the muscular coat 

 of the intestines. When that action is simply increased through the whole 

 of the canal, the food passes more rapidly, and purging is produced; 

 but the muscles of every part of the frame are liable to irregular and 

 spasmodic action, and the muscular coat of some portion of the intestines 

 may be thus affected. A species of cramp may attack a portion of the in- 

 testines. The spasm may be confined to a very small part of the canal. 

 The gut has been found, after death, strangely contracted in various places, 

 contraction not extending above five or six inches in any of them. In 

 the horse, the ileum is the usual seat of this disease. It is of much import- 

 ance to distinguish between spasmodic colic and inflammation of the 

 bowels, for the symptoms have considerable resemblance, although the 

 mode of treatment should be very different. 



The attack of colic is usually very sudden. There is often not the slightest 

 warning. The horse begins to shift his posture, look round at his flanks, 

 paw violently, strike his belly with his teet, lie down, roll, and that fre- 



