iS8 THE INFANCY OF ANIMALS 



a circular area at the end of the shell, which can then be 

 thrust off like a lid. 



The reality of the mother's regard for her young was 

 attested long since by the naturalist Voeltzkow, who built 

 a fence around one of these nests near hatching time. 

 Each night, on her return, she broke down the fence, even 

 though each fence was made stronger than the last. Finally 

 the nest was found to have been deserted, and then it was 

 discovered that she had dug a hole beneath the fence and 

 thence had led her brood away to safety. 



Young alligators have a somewhat different upbringing, 

 and would seem to receive less of the maternal attention. 

 They are hatched like young crocodiles under a mass of 

 earth, but in this case the nursery is formed not by ex- 

 cavating a hole in the ground, but by scraping up a mass 

 of dead leaves, twigs and fine earth, till a mound some 

 three feet high and as much as eight feet in diameter is 

 formed. On the top of this mound, some eight inches 

 from the surface, some twenty or thirty white, hard- 

 shelled eggs are laid, and are there left to incubate by the 

 heat generated by the decaying vegetable matter. As 

 soon as the young escape from the shell they readily make 

 their way through the light soil covering them, and run 

 to the water without any further care on the part of the 

 mother. All this time, however, she has not been indifferent 

 to their welfare ; on the contrary, the eggs have been most 

 jealously guarded and with less ostentation than in the 

 case of the crocodile, for instead of lying over the spot 

 which hides the eggs, she digs a hole in the river bank 

 within a foot or two of the mound, and there awaits possible 

 marauders. 



Altogether about 2,600 species of reptiles are living 

 to-day, and of this great host, only in one or two species 



