OF MAMMALIA. 235 



and, taking on the form of the parent, remain until they have 

 attained to a certain degree of development, and then make 

 their exit through the vaginal outlet (vg). For the nourishment 

 of their young the warm-blooded Vertebrates possess an organ 

 for the secretion of milk, which is called the mammary gland, 

 (mm,) and which, in such animals as the cow, sheep, and goat, 

 is known as the milk-bag; and either hangs, as in most of the 

 quadrupeds, between the hind legs, or extends to a greater or less 

 distance along the belly. Among the higher groups the mam- 

 mae lie between the fore limbs. 



