144 THE STORY OF REPTILE LIFE. 



nourished by the remains of the food yolk of 

 the egg. Not until this is absorbed do they 

 commence to feed, their first meal consisting of 

 aphides, and similar tiny creatures. At birth it 

 should be mentioned, they are less than an inch 

 in length. 



We may pass now to a brief survey of another 

 side of reptile domestic life their sociability. 

 Reptiles are far less frequently found dwelling 

 in colonies or living in large herds than birds 

 or mammals. Perhaps the most remarkable 

 instances are the great " warrens " of the Sand 

 Iguana of the Galapagos (Conolophus subcristatus), 

 and the enormous herds of an allied form living 

 on the same islands, Amblyrhynchus cristatus. 

 The former Darwin found to be so numerous 

 on James Island that "we could not for some 

 time find a spot free from their burrows on 

 which to pitch one single tent." The latter 

 are still abundant, and may be seen swarming 

 in masses of thousands on the rocks fringing the 

 sea. Similarly the Crocodilia and certain species 

 of sea-snakes consort together in enormous 

 numbers ; as also did the Tortoises of the 

 Galapagos a couple of centuries ago. These 

 huge crowds, however, are not gathered together 

 for mutual protection or love of their kind ; they 

 are simply the result of unchecked increase, there 

 being room and food enough for all, and no 

 enemies sufficiently powerful to keep down their 

 numbers. 



In other cases, however, mutual advantage is 

 evidently the inciting cause to the gathering 

 together of large numbers of the same specie. 



