22 ANIMAL LIFE 



In the rivers and swamps armoured newts arose 

 and wandered over the damp coal-forests and lake 

 shores as the alligators do to-day, whilst their descend- 

 ants, the multitudinous frogs and toads, have still 

 only partially emancipated themselves from aquatic 

 life in order to gain that life on land which favours the 

 height of animal development and gives it new impetus 

 and variety. 



The history of reptiles is a chronicle of more 

 stirring events. From a remote epoch, and dim as 

 all such origins are, the first reptiles appear, almost 

 indistinguishable from the armoured newts, their 

 contemporaries. They were the colonists of those 

 days, and, with an adaptive power of meeting new 

 circumstances that the newts had never shown, 

 became masters not only of the swamps but of the 

 sea and land. Some grew to the size and acquired 

 the habits and shape of whales. On land they stood 

 upright, high as houses, and with their hands reached 

 to the greener boughs of lofty trees. That most 

 difficult of all such conquests, the dominion of the 

 air, they effected, and in their own way solved the 

 problem of ilight. Success such as this opened up 

 still other paths of life, for which further variety of 

 form was needed. Small as well as great could find 

 places in these newly acquired kingdoms. The 

 development of vertebrate life seemed a lasting work, 

 finished in its main outlines. 



Yet in this heyday of reptilian life another group, 



