BIRDS 



329 



Lizards have long bodies with a distinct head, neck, and 

 tail. Their feet have five toes each. Turtles have a 

 peculiar form, and move slowly, because of their protective 

 box of horny material. In temperate climates, reptiles 

 hibernate in winter. 



Snakes have the remains of bones which show that their ancestors 

 once had limbs; but modern snakes have no limbs. In spite of this 

 they move rapidly. The body of the snake is so narrow that there is 

 little room for some of its internal organs, so these are altered. Thus, 

 one lung is very small, and almost useless. On the other hand, the 

 long muscular body is a wonderful structure for the seizing and crush- 

 ing of prey. Most small snakes are harmless. The dangerous ones in 

 this country are rattlesnakes, water moccasins, and copperheads. In 

 India there is a great python, and in South America, the anaconda, 

 which grows to a length of 30 feet. These kill their prey by crushing it. 



Reptiles reached an enormous size in past geological times, as their 

 fossils tell us. There were then 

 swimming, walking, and flying 

 reptiles. 



344. Birds. In certain 

 rocks there have been found 

 the remains (fossils) of birds 

 that are remarkably like 

 reptiles. They have a long, 

 jointed tail, as reptiles have, 

 and the tail feathers come in 

 pairs from these joints. In 

 modern birds (Fig. 269) the 

 tail joints are so much short- 

 ened that all the feathers 

 seem to come from one place. 



Skull. 



Clav.cle 



Sternum 



Fio. 269. 

 Skeleton of a Bird. 



These fossil birds had teeth 



like those of reptiles ; modern birds have only a horny beak 



