THE ALIMENTARY CANAL. 



lower animals, the intestines lie more or less loose in the 

 abdomen ; but in the Crocodile, and likewise in Birds and 

 Mammals, they are supported by a membrane called mes- 

 entery. 



Fio. 48. Anatomy of the Carp : br, branchiae, or gill-openings ; c, heart ; /, liver; vn, 

 vn' t swimming-bladder ; ci, intestinal canal; v, ovariuin; it, ureter; a, anus; o', 

 genital opening; u', opening of ureter. The side-view shows the disposition of 

 the muscles in vertical flakes. 



