54 IN THE GRIP OF AN ICE AGE 



underground, to become the coal seams of man's early 

 industrial age. Nearly every type of the old vegeta- 

 tion was blotted out. We can trace some of the ferns 

 and other trees gradually becoming hardier. We 

 find pines and yews and firs, or their ancestors, now 

 for the first time appearing on the earth. But it 

 was a very thin diet they provided compared with 

 what had gone before, and the fat salamanders and 

 insects and other large-feeding, sluggish animals went 

 the way of all flesh. Only a few types were pre- 

 served in warmer regions, to give us the amphi- 

 bians, stick insects, beetles, spiders, etc., of the new 

 age. 



It was a great annihilation. Up to that time in the 

 story of the earth motherhood consisted merely in 

 shedding eggs on the surface of the earth or in its 

 waters. To put it poetically, * ' nature ' ' mothered the 

 eggs. The warm ground or water gave heat enough 

 to stimulate the wonderful mechanism in the eggs. 

 In the colder age we are considering there would not 

 be heat enough. Even if the mother got sufficient 

 food to reach the egg-laying stage, the old habit of 

 entrusting the eggs to nature was out of date; ex- 

 cept, as I said, in favoured localities which kept the 

 old conditions more or less, and must have been 

 greatly overcrowded. A new habit, the practice of 

 caring for one's eggs or young, was needed in a cold 

 climate. 



Then there was the direct effect of the cold. The 



