3QO GENERAL SCIENCE 



they hide in the water and breathe through their skin; 

 since their activity is slight they do not require much 

 oxygen. The toads hide away in holes in the ground 

 during the winter and are in an almost lifeless condition. 



The idea that it rains toads came into existence because 

 the toad tadpoles can change from the tadpole stage to 

 the adult form in about 24 hours. If a rainy season or 

 heavy shower occurs just at the time when they are 

 changing from the tadpole to the adult stage, the roads or 

 fields about ponds, where the tadpoles are numerous, are 

 alive with young toads hence many persons concluded 

 that the toads were rained. 



269. Economic Value of Amphibians. Frogs serve 

 as food for man; they also devour great numbers of 

 insects which would be harmful to plants that man grows. 

 Toads, since they travel over land away from the water, 

 are of much greater value than frogs in destroying insects. 

 Several toads in a garden will keep it almost clear of the 

 harmful insects which prey upon valuable plants. 



270. Reptiles. Common examples of reptiles are 

 snakes, turtles, and alligators. They have an internal 

 skeleton and a scaly covering; the turtles in addition have 

 a bony covering. Reptiles are close relatives of birds. 

 They reproduce by eggs which have a tough covering and 

 contain considerable food for the young while in the 

 process of incubation. Snakes usually deposit their 

 eggs in holes made in the ground; tortoises do the same. 

 Some snakes are poisonous, such as the rattlers, copper- 

 heads, and blowing vipers. The rattlesnake makes a 

 noise with its rattles when it is disturbed, to give warning 

 before it attempts to bite. An additional rattle is added 

 each year after the third year. Copperheads give no 

 warning whatever, but conceal themselves in order to wait 



