THROUGH THE GEOLOGIST'S EYES 



has its root in that which preceded it. There were 

 rude, half -defined fishes in the Silurian, and probably 

 the beginning of amphibians in the Devonian, and 

 some small mammalian forms in the Mesozoic time, 

 and doubtless rude studies of the genus Homo in 

 Tertiary times. Nature works up her higher forms 

 like a human inventor from rude beginnings. Her 

 first models barely suggest her later achievements. 



In the vegetable world it has been the same; from 

 the first simple algse in the Cambrian seas up to the 

 forests of our own times, the gradation is easily 

 traced. Step by step has vegetable life mounted. 



The great majority of the plants and animals of 

 one period fail to pass over into the next, just as our 

 spring flowers fail to pass over into summer, and 

 our summer flowers into fall. But the law of evolu- 

 tion is at work, and life always rises on stepping- 

 stones of its dead self to higher things. 



