DIGESTIVE SYSTEM. 329 



greater surface, and aid the action of the lacteals, the inner 

 coat of the intestine is villous, and likewise covered with 

 various rugae, which have been termed valvulce conniven- 

 tes. The villi possess a vascular structure, and, when 

 destitute of chyle, have been compared to little loose pen- 

 dulous bags. It is this villous coat, which, when there is 

 a separation of the intestines into large and small, character- 

 ise the latter. In the duodenum and jejunum, the chyme 

 acquires the nature of chyle, and in the ilium the separation 

 is completely effected between it and the faeces. These last 

 consist of the useless part of the food, coloured by the union 

 of a part of the bile, which is never reabsorbed. When the 

 lacteals have finished the absorbing process, the fasces now 

 leave the portion of the intestine destined for digestion, and 

 enter the larger intestines, which are storehouses, in which 

 the useless part of the food is placed until it can be conve- 

 niently evacuated. The larger intestines are characterised 

 by their superior dimensions and strength, but more par- 

 ticularly by the absence of the villous coat. 



The larger intestines are divided into three parts, the 

 ccecum, colon, and rectum. The upper extremity of the 

 colon is closed, and as the ilium enters laterally and a little 

 way from the end, the head of the colon consequently 

 forms a blind gut or ccecum. Sometimes there is attached 

 to this caput coecum coli, another tubular appendage closed 

 at its free extremity, termed appendix vermifonnw. The 

 orifice of the ilium where it enters the colon is furnished 

 with folds, which probably regulate the quantity of matter 

 discharged into the colon, and prevent regurgitation. 

 These folds constitute what is termed valvula coli. When 

 the faeces have undergone all the changes which are neces- 

 sary in the colon, and traversed its tortuous cavity, they 

 enter a portion of the intestine, which, from the straight- 

 ness of its course, is termed the reclum, which opens ex- 

 ternally by the anus. 



