GEOLOGY IN SERVICE OF MAN WATTS 289 



the whole history of life on the earth. As with antiquarian research, 

 each new discovery in geology, whether on the physical or the bio- 

 logical side, only brings these distant ages more fully into view and 

 emphasizes their modernity and their likeness to our own time. 

 Hutton's famous dictum that he saw " no vestige of a beginning, 

 no prospect of an end," is to-day more true than ever, when we 

 regard the evidence of stratified rocks. But we know enough to 

 convince us that Avithin post-Cambrian time evolution has steadily 

 proceeded from general to special, from simple to complex, from 

 lower to higher efficiency. 



In almost every subdivision of the animal kingdom, and in not 

 a few branches of the vegetable kingdom, lines of descent and 

 directions of specialization have been made out, sometimes visibly 

 operatnig throughout whole Sj^stems, but more usually through 

 smaller divisions of the record; and this in the former kingdom 

 not only among vertebrates but among the invertebrates and even 

 their lower subkingdoms. It may even be stated that in methods 

 of defense, in food procuring, in the attainment of favorable posi- 

 tions and attitudes, something very closely imitating what would be 

 expected on the doctrine of the origin of species by "survival of the 

 fittest " has again and again occurred. 



The essence of evolution is unbroken sequence, and Avhen Ave con- 

 sider the extraordinary delicacy of the adjustment of life to its 

 physical and organic environment, the mutual interdependence of 

 life forms, and the necessity to them of such factors as favorable 

 range of temperature, food, climatic conditions, soil, and the con- 

 tinuity of the "element" in or on which they live, it is most Avon- 

 derful that in the vast lapse of post-Archaean time it has been 

 possible for life to exist continuously and continually to evolve, 

 throughout those long ages. And this in spite of the fact that, 

 although the main chain has been unbroken, conditions have, in 

 many cases, been so unfavorable that whole groups have flourished 

 and died out, while others haAC become so attenuated that only a 

 fcAv surviA'ors haA^e been left, highly restricted in distribution, to 

 burgeon out again Avhen the unfavorable conditions Avere removed, 

 or in other places Avhere conditions have again become more favor- 

 able to them. 



That life has survived continuously in spite of the vicissitudes 

 through which it has been compelled to pass, and the frequent con- 

 A^ergence upon it of unfaA'orable conditions, may Avell be taken to 

 heart by those who fear that civilization Avill be brought to an end 

 by the misuse of the poAAers that itself has evolved. They may 

 surely take courage and trust that the remedy for these evils will 

 come, as it has in innumerable other cases, not from conventions 



