128 BEGINNERS' ZOOLOGY 



In what state of growth are the legs when the tadpole 

 first goes to the surface to breathe ? Which legs appear 

 first ? Of what advantage is this? What becomes of the 

 tail ? Is the tail entirely gone before the frog first leaves 

 the water ? Are tadpoles habitually in motion or at 

 rest ? 



Is the intestine visible through the skin ? (Fig. 249.) 

 Is it straight or coiled ? Remembering why some fish 

 have larger intestines than others, and that a cow has a 

 long intestine and a cat a short one, state why a tad- 

 pole has a relatively longer intestine than a frog. 



Compare the mouth, jaws, eyes, skin, body, and habits 

 of tadpole and frog. 



Frogs 



Prove that frogs and toads are beneficial to man. Did 

 you ever know of a frog or a toad destroying anything 

 useful, or harming any one, or causing warts? How 

 many pupils in class ever had warts? Had they handled 

 frogs before the warts came? Frogs are interesting, 

 gentle, timid animals. Why are they repulsive to some 

 people? 



Environment. — Where are frogs found in greatest 

 numbers? What occurs when danger threatens them? 

 What enemies do they have? What colour, or tint, is most 

 prominent on a frog? Does the colour "mimic" or imi- 

 tate its surroundings? W 7 hat is the colour of the und^r 

 side of the body? (Fig. 250.) Why is there greater 

 safety in that colour? What enemies would see water frogs 

 from below? Do tree frogs mimic the bark? The 

 leaves? 



Can a frog Stay under water for an indefinite time? 

 Why, or why not? What part of a frog is above the 



