TURTLE TRAITS 131 



surrounding edges a new covering of horn grows 

 out. One third of the entire shell has been known 

 to be thus replaced. 



Although so slow in their locomotion and 

 actions, turtles' have well-developed senses. They 

 can see very distinctly, and the power of smell is 

 especially acute, certain turtles being very dis- 

 criminating in the matter of food. They are also 

 very sensitive to touch, and will react to the least 

 tap on their shells. Their hearing, however, is 

 more imperfect, but as during the mating season 

 they have tiny, piping voices, this sense must be 

 of some use. 



Water tortoises can remain beneath the surface 

 for hours and even days at a time. In addition 

 to the lungs there are two small sacs near the tail 

 which allow the animal to use the oxygen in the 

 water as an aid to breathing. 



All turtles lay eggs, the shells of which are white 

 and generally of a parchment-like character. They 

 are deposited in the ground or in the sand, and 

 hatch either by the warmth of the decaying vege- 

 tation or by the heat of the sun. In temperate 

 countries the eggs remain through the winter, and 

 the little turtles do not emerge until the spring. 

 The eggs of turtles are very good to eat, and the 

 oil contained in them is put to many uses. In all 

 the countries which they inhabit, young turtles 

 have a hard time of it ; for thousands of them are 

 devoured by storks, alligators, and fishes. Even 



