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The Living Things of the Earth unit i 



\'\G. 40 (above) These tadpoles arc the yonn 

 of the <j;ree/i frof^. How do they differ fro/// on 

 adult frog? (HUGH spencer) 



of some unwary animal along the banks 

 will quicklv^ rouse them to activity. 



Turtles. Turtles have a complete back- 

 bone, ribs, and all the other bones you 

 should expect a vertebrate or a "back- 

 boned" animal to have. The siicll de- 

 velops from the skin of the uppei* and 

 lower surfaces and becomes attached 

 to the backbone and the ribs. Head and 

 legs are, of course, covered \\'ith the 

 ordinary scales characteristic of reptiles. 

 Turtles may eat plants, insects, frogs, 

 fish, or any other small animals. Their 

 horny, toothless jaws are sharp and 

 strong and are used for tearing and 



Fig. 41 (left) The s/iappi//ir turtle is fo/i//d in 

 ponds or rivers. It has a d/ill hroivvish shell iviti? 

 //otches at the back. Why are turtles classed as 

 reptiles? (.-vmerican museum of natural his- 

 tory) 



biting, much as teeth are used by othtr 

 animals. In a few species the shells re- 

 main soft. To become better acquainted 

 with reptiles read one of the books 

 listed in the bibliography. 



CLASS - AMPHIBIANS 



How we can recognize amphibians 



Amphibians, like reptiles, are cold- 

 blooded vertebrates. Their skin is naked 

 and in almost all species is soft and 

 moist. They are called amphibians be- 

 cause most of them spend the first part 

 of their life in the water and the other 



