40 THE STORY OF REPTILE LIFE. 



curve the neck round to the right or left bring- 

 ing it and the head under the eaves of the 

 "carapace," hence the name side-necked tor- 

 toises. Of course in this way the whole of one 

 side of the head and face is exposed. In most 

 land-tortoises this would be a grave danger, but 

 apparently in the aquatic regions the need for 

 such effective protection is less urgent. 



When, probably owing to overcrowding, some 

 of the more adventurous tortoises essayed to 

 make a living by the margins of pools and 

 shelving banks of streams, and eventually in 

 the water itself, they apparently found it ex- 

 pedient to exchange a vegetable for an animal 

 diet, inasmuch as the water-tortoises of to-day 

 are almost entirely carnivorous. To the car- 

 nivorous habits we may trace further peculiarities 

 in the development of new traits of character 

 called forth by the very different nature of the 

 food. Preying on other living creatures, often 

 more active and highly organised than them- 

 selves, their only chance of success is, not 

 seldom, by cunning. 



An admirable instance of this is furnished by 

 the Snapping Turtle or " Snapper " (Chelydra 

 serpentina), one of the largest of the pond- 

 tortoises. Fishes are decoyed within striking 

 distance by the artful display of two temptingly 

 worm-like filaments protruding from the tip of 

 the tongue, the rest of the animal being con- 

 cealed in the mud. The consequences of touching 

 these are far more serious than treading on the 

 tail of the Irishman's coat! Larger prey this 

 diabolical monster captures by stealthily ap- 



