CHAPTER IV. 

 EXCRETION. 



The expulsion of waste products from the body is by- 

 means of a, the feces (duug); b, the urine; c, the sweat; 

 d, respired (breathed) air, and is termed excretion. 



A. By the feces (dung). In the description of the 

 digestive tract the food had to be taken as far as the 

 great colon, where it was stated some absorption might 

 take place, from there back, however, the remainder 

 of the food ingested cannot be acted upon for various 

 reasons, such as the previous extraction of all the 

 nutritive matters, etc. The division of the intestinal 

 canal behind the great colon is the floating colon, located 

 in horses in the left flank, in cattle and sheep the 

 upper part of the left flank is occupied by the paunch. 

 This colon has a number of tightenings (constrictions) 

 in its walls, due to certain circular muscular fibres. 

 It will be remembered that the entire intestinal tract 

 is a musculo-membranous tube, and that long and cir- 

 cular muscular fibres enter more or less into the con- 

 struction of it. It has also been stated that muscles con- 

 tract and relax, hence it would be expected that the 

 intestines would have a certain amount of movement, 

 such is true, there is a constant worm-like motion in the 

 intestinal walls during life; unless paralyzed such move- 

 ment is known as peristalsis, or the peristalic, (vermicular 

 or worm-like) movement of the bowels. As a result of this 



