208 



Handbook of Nature-Study 



THE TURTLE 



Teacher's Story 



TURTLE is at heart a misanthrope; its shell is in itself, proof of 

 its owner's distrust of this world. But we need not 

 wonder at this misanthropy, if we think for a moment 

 of the creatures that lived on this earth, at the time 

 when turtles first appeared. Almost any of us would 

 have been glad of a shell in which to retire, if we had 

 been contemporaries of the smilodon and other monsters of earlier 

 geologic times. 



When the turtle feels safe and walks abroad for pleasure, his head pro- 

 jects far from the front end of his shell, and the legs, so wide and soft that 

 they look as if they had no bones in them, project out at the side, while 

 the little, pointed tail brings up an undignified rear; but frighten him, 

 and at once, head, legs and tail all disappear, and even if we turn him over, 

 we see nothing but the tip of the nose, the claws of the feet and the tail 

 turned deftly sidewise. When frightened, he hisses threateningly; the 

 noise seems to be made while the mouth is shut, and the breath emitted 



through 



the nostrils. 



Carapace of painted terrapin in retirement. 



Plastron of same terrapin. 



The upper shell of the turtle is called the carapace and the lower shell, 

 the plastron. There is much difference in the different species of turtles 

 in the shape of the upper shell and the size and shape of the lower one. 

 In most species the carapace is sub-globular but in some it is quite flat. 

 The upper shell is grown fast to the backbone of the animal, and the 

 lower shell to the breast bone. The markings and colors of the shell offer 

 excellent subjects for drawing. The painted terrapin has a red-mottled 

 border to the shell, very ornamental; the wood turtle has a shell made up 

 of plates each of which is ornamented with concentric ridges; and the box- 

 turtle has a front and rear trap-door, hinged to the plastron, which can 

 be pulled up against the carapace when the turtle wishes to retire, thus 

 covering it entirely. 



