60 THE BRONTOSAUR AND ITS COUSINS 



scribed in all our newspapers a year ago. I am, as 

 usual, not so much going to describe these things as 

 to explain them. 



We saw that reptiles had been developed from 

 amphibians in the latter part of the coal forest age. 

 They were a plain response to the change of con- 

 ditions. Dry land was increasing. The salamander 

 took to dry land, and became a reptile. But the dry 

 land increased so much, and rose so high, that it 

 threatened to strangle the new monarch of the earth 

 very speedily. Fortunately for him, there were still 

 warm regions, and there he awaited his turn. I im- 

 agined a group of reptile scientists keeping accounts. 

 For a hundred thousand years or more they would 

 report increasing cold, and dire would be the pro- 

 phecies. Then for a hundred thousand years or more 

 they would report decreasing cold, and hope would 

 animate the chilly reptile breast. Never believe 

 prophets who venture more than forty-eight hours 

 ahead. (In the end of this work I will venture ten 

 million years ahead — but that is different.) 



The sun shone again upon the whole world. The 

 new age was not as hot as the previous one, for the 

 atmosphere was now purified of its great masses of 

 carbon and moisture. But it was again perpetual 

 summer all over the earth ; no cold or frost or winter 

 anywhere. It was more brilliant sunshine than be- 

 fore. Sombre trees like the yews and firs remained in 

 temperate regions, but the new types of trees — very 



