CROCODILES. 47 



Though in general appearance Crocodiles look 

 very much like gigantic lizards, yet a closer 

 examination will show that this resemblance is. 

 rather accidental than due to a community of 

 descent. The peculiar lizard-like form we must 

 regard as the common inheritance of all the 

 reptiles; and variations on this are the result 

 of modification in adaptation to environment. 



Among living Crocodiles and their direct 

 ancestors, the rough outline of this primitive 

 form have been more or less faithfully pre- 

 served, and this because they have escaped 

 extreme specialisation in any one direction. 

 Though aquatic in habits, yet, like the Newts 

 among the Amphibia, the land has never been 

 entirely forsaken. Among living Crocodiles the 

 shore is the repository for the eggs, and to 

 the shore they resort for the daily sun-bath. 

 Further, they are frequently compelled to travel 

 overland in search of water when the streams 

 which give them harbour dry up. That their ex 

 tinct ancestors, and the yet older forms which 

 preceded them, led similar lives, is almost certain. 

 Indeed evidence is forthcoming which makes this 

 conclusion irresistible. 



If, superficially, the changes which the environ- 

 ment has effected are not great, yet direct adapta- 

 tions to environment can be easily discovered. 

 Externally the most obvious are the webbed 

 feet, the bony armour, and the enormous tail, 

 which is used as a propeller ; and after these 

 the position of the eyes and nostrils. Internally 

 modifications of the skull and of the soft part of 

 the palate have taken place, which enable the 



