INTRODUCTION xxi 



A QUADRUPED is a mammal which possesses four feet, or, hav- 

 ing two hands and two feet, like the apes, yet walks upon all fours. 



Man is a biped, or two-footed animal. Land mammals gen- 

 erally are quadrupeds, or four-/oofed, and monkeys are quadru- 

 manous, or four-handed. 



The term quadrumana is often applied to apes and monkeys 

 because the long great toe on the hind foot makes the foot quite 

 hand-like in its grasping power. 



A BIRD is a warm-blooded animal, which comes from an egg 

 that usually is laid and hatched by the parent. It breathes air, 

 is covered with feathers, usually is provided with wings, and all 

 save a few species can fly. 



A REPTILE is a cold-blooded, egg-laying animal, usually covered 

 with scales or a bony shell. All have lungs and breathe air, but some 

 are able to live in water so comfortably they are called amphibious. 



AN AMPHIBIAN is a member of the Class of animals which forms 

 a connecting link between reptiles and fishes. Some breathe air, 

 and live alternately on land and in water, like frogs. Others have 

 gills, and live in water all their lives. A few are capable of devel- 

 oping either gills or lungs, according to the presence or absence of 

 water, like the wonderful Axolotl of Mexico. 



A FISH is a cold-blooded animal, possessing gills, fins, and 

 (usually) scales. All save a very few species live permanently in 

 water. The exceptions are certain fishes in the East Indies which 

 for short intervals hop about on land, or even climb rocks or trees! 



GRAND DIVISIONS OF THE ANIMAL WORLD 



BRANCHES CLASSES 



Mammals 



Birds 



Reptiles 



VERTEBRATES i Amphibians 



Fishes 



Myzonts 



Lancelets 



