Absorption. 187 



extent, as in the mesentery, before entering the circulation. 

 There is, at any rate, a well-developed lymphatic system in 

 the walls of the large intestines ; it is possible, therefore, 

 that material is taken up in the large intestines both 

 through the bloodvessels and lymphatics, and that this 

 absorption is something considerable may be readily under- 

 stood when we remember the size of these bowels and the 

 nature of their contents ; in the caecum, for instance, the 

 contents are fluid, derived largely from the water consumed, 

 and we know that this is readily taken up into the system, 

 the path in this instance being probably exclusively by the 

 bloodvessels. 



Absorption from the large intestines is active ; we have 

 given reasons for believing that it may be lymphatic as well 

 as capillary. That substances can be taken up with ex- 

 treme rapidity from the large bowels is a well-known fact ; 

 anaesthetics, such as ether, may be administered to the 

 horse per rectum. Colin observed that 18 minutes after 

 injecting a solution of nux vomica into the caecum con- 

 vulsions began, and 8 minutes later the animal was dead. 



The absorbent surface of the large intestines is equal to 

 75 square feet, and, according to Colin, each square yard 

 collects 16 i lbs. of solid and liquid matter in 24 hours in 

 both horse and ox. This observer gives a table showing 

 the solid and liquid material poured into the intestinal 

 canal in 24 hours, from which we may judge that the 

 enormous absorbent surface to which it is exposed is none 



too large : 



Diet - - - 26 lbs. 



Water consumed - 66 



Saliva - - - 92 £ 



Gastric juice - - 11 



Bile - - - 11 



Pancreatic juice - - 11 



Intestinal juice - - 22 



Returning, however, to the small intestines, it has been 

 observed by Colin that in the horse, almost immediately 

 after food has been given, waves of chyme are passed into 

 the duodenum, and at once the lacteals in the mesentery in 



