92 



FIRST LESSONS IN ZOOLOGY 



villi, in which arc blood-vessels, and other absorbent ves- 

 sels for taking up the digested food. The small intestine 

 empties into the large intestine, which has an enlargement 

 called the ca;cum. The large intestine and the ca;cum 

 together form the last section of the alimentary canal and 



aLc 



Fig. 56. Fk;. 57. 



Yii.. c;6. — A iLatworm {Plnnaria) tc show braiiched alimentary canal, al.c. 



(About natural sizu; after Hatshek. ) 

 Fig. 57. — Alimentary canal of a cow; <^ rumen (left hemisphere); /', 



rumen (right hemisphere); c, insertion of ceso- phagus; t/, reticulum; 



e, omasum; /, aboniasum ; ^, duoiienum ; h and /, jejunum and 



ili-um; j. cajcum; /■, colon with its various convolutions; /, rectum; the 



wh(j!e canal about 150 feet long. 



retain the remaining food substances for some time to 

 allow of more compl<;te absorption of the digested foods. 

 The alimentary canal of the rabbit, with all its folding and 

 branchings into large glands and millions of small ones, 

 furnishes a surface for secretion and absorption A'er\' man\' 

 times the external surface of the body. In brief, the area 



