The Mammal. 125 



or foe), the dog, the cat, the elephant, the wolf, 

 the bear, the lion, the tiger, and lower down in 

 the scale, the rabbit, the squirrel, the mouse with 

 his big brother the rat, and all the furry deni- 

 zens of fields and woods. The whales, too, be- 

 long to this class, and the porcupine, although so 

 disguised by its forbidding spines, and the bat, 

 in spite of its wings, and the armadillo, in spite of 

 its turtle-like covering, with many others. 



The mammal is warm-blooded, like the bird, but 

 unlike the bird it brings forth its young alive and 

 nourishes them with milk secreted by the mam- 

 mary glands. It is from these glands, or mam- 

 mae, as their external forms are called, that this 

 division of the animal world gets the name of 

 mammal. 



The higher and more complex the life, the 

 greater the effort to reproduce it, and the more 

 elaborate the devices for conserving the reproduc- 

 tive material. 



The lavish waste seen in the fish and other forms 

 is discreetly avoided by the bird ; the loss which 

 the insect sustains because of its exposed and 

 orphaned eggs, the bird also avoids by the exer- 

 cise of intense parental solicitude. 



In the mammalian life the conservation of the 

 reproductive material is, as would be expected, 

 carried to a yet higher degree. 



Although apparently so different from other 

 forms of life, the mammal too issues from an egg. 



