88 THE HAUNTS OF LIFE 



has weighed some up to 940 Ib. and measured 

 some up to 7 feet in length. All these are 

 doubtless the descendants of land tortoises, 

 for they breathe dry air as terrestrial animals 

 do, and they give away their secret in the fact 

 that they all come to the shore to lay their 

 eggs in the sand. Animals that have found a 

 new kind of home usually go back to the old 

 home to breed. Whales evade this law be- 

 cause the mother carries her young one for a 

 long time before birth, so that when it is born 

 it can swim for itself. 



SEA-SNAKES AND SEA-SERPENTS 



Turtles have their legs flattened into flip- 

 pers, the oars by which they swim; whales 

 have their fore-limbs flattened into flippers, 

 which are chiefly used in balancing, the pro- 

 peller being the tail; snakes have no limbs, 

 but it is interesting to find that the sea-snakes 

 show a marked flattening in the tail region, 

 and sometimes in the posterior part of the 

 trunk as well. In all cases the meaning of the 

 flattening is the same; it is an adaptation 

 which secures a good grip of the water. The 

 sea-snakes are mostly fish-eaters, and very 



