MANUAL OP NATDRB STUDY. 55 



separate glass jars, pass them around the room for 

 the children to examine. What sort of covering 

 has the snake? The fish ? The frog ? Will the 

 fish and frog shed their skins as will the snake ? 

 The teacher should be able to secure some cast ofi" 

 snake skins for examination. Do the scales of the 

 fish assist that animal in its movements through the 

 water ? Do the scales of the snake help in motion ? 

 Which way do the scales slope ? Why not forward 

 instead of backward? Where does a fisherman 

 begin to scrape the scales from a fish? Why? 

 Could we scrape the scales from a snake in that 

 way ? Is the skin of the frog scaly ? Why would 

 not scales be an advantage to the frog as well as to 

 most fishes? Where do fishes live? Frogs? 

 Snakes ? Touch the frog's eye with anything soft. 

 Has it any lids? Of what kind? .Touch the 

 snake's eye in the same way. The fish's eye. 

 Why should not these animals as well as frogs and 

 turtles have lids to draw over their eyes? Try 

 turtles. Why should not the frog and turtle have 

 upper lids as well as under lids ? Notice the round, 

 smooth spot just back of the eye in the frog. Do 

 you find any such spot on the snake or fish? See 

 if you can find such a spot on the grasshopper. 

 Look just above where the long leg joins the thorax. 

 Frogs and grasshoppers can hear, but that matter 

 is still in doubt in regard to snakes and fishes. 



