46 LAND LIFE BEGINS 



reduced. Food is less, and it must be hunted. Can- 

 nibalism is apt to begin, and the struggle of hunter 

 and hunted brings out new forms, just as surely as a 

 great war does. 



^ So we find the amphibia of the coal forests branching 

 out in many directions. Some small types become 

 tree climbers, and no doubt they found a rich diet of 

 insects in the trees. This reacted on the insects, and 

 caused fresh developments among them. Some, as 

 we saw, developed wings, and could at least soar from 

 tree to tree. As these enjoyed good security, for 

 there were then no birds or flying reptiles, it is 

 natural to find them growing to a large size. They 

 had fat, heavy bodies eighteen inches long. Other 

 insects were fitted for survival by gradually develop- 

 ing such a shape and colour that they could not be 

 seen at any distance. These were the "stick insects " 

 which belong to the ancient order. They are very 

 common in Australia to-day, precisely because Aus- 

 tralia and New Zealand have the most primitive 

 animal populations on the globe. 



Other amphibia of the coal forest lost the use of 

 their limbs, and developed long snake-like bodies. 

 These give us an excellent clue to the development of 

 the later serpent. The struggle for life among the 

 amphibians themselves had become very severe, and 

 some had taken to hiding and living among the ex- 

 posed roots of the trees by the side of the swamps. If 

 you have ever seen a picture of a mango forest at a 



