THE COMING OF EVOLUTION 201 



like London from about 80 per thousand two centuries 

 ago to the present figure of some 15 per thousand. 

 From the scientific aspect, the great alteration 

 has been the opening up of a whole new world of 

 organic life, previously undreamed of, existing in close 

 contact with, and indeed thriving upon, the animal 

 world previously believed to represent the sum total 

 of life on this globe. The principal features of this 

 discovery were the minute size of the organisms, by 

 which they have hitherto escaped notice, their in- 

 calculable numbers, and the rapidity and simplicity 

 of their reproductive methods, which enable them, 

 despite their invisibility, to become, when they are 

 of harmful nature, the most formidable enemies of the 

 human race. 



By his attempt to give a rational theory of the 

 origin of the solar system, Laplace directed men's 

 attention to the existence of the problem, 

 and thus led to a quickened interest in 

 the study of the earth itself a study which had 

 already begun to make some headway. Unfortunately, 

 the countries in which freedom of thought had most 

 prevailed against the claims of papal authority were 

 also those in which the tyranny of the theory of the 

 verbal inspiration of the Bible had been most firmly 

 established, and a new contest, in which, however, 

 the final issue was never doubtful, had therefore 

 to be waged before any view of the earth's origin, 

 other than that to be found in the book of Genesis, 

 could win a general approval. Even in the early 

 years of the nineteenth century, it was seriously 

 contended that the fossils had been hidden in the 



