FIFTY YEARS OF AMERICAN SCIENCE 17 



have scanned our incomparable drift plains and drumlins, 

 moraines and kames, sand plains and paha, and have solved 

 the riddle of the loess ; and during the last quarter century the 

 records of the ice ages have been more thoroughly scrutinized 

 and more fully interpreted in America than in all the rest of 

 the world. Meantime, too, geology ramified in other direc- 

 tions, and its applications multiplied; the second half of the 

 nineteenth century is distinguished by activity in investiga- 

 tion of rocks and resources in every country, but especially in 

 America, with its federal survey and score of state surveys, 

 maintained at a cost of more than a million dollars annually, 

 and enriching the nation at an indefinitely larger rate. It is 

 fair to remember that the success of the science on this conti- 

 nent is largely due to the great continental expanse and the 

 wide distribution of resources in the rocks; that the plateau 

 region and the canyon country of the southwest furnish the 

 best knowai record of geologic process; that the Appalachian 

 region affords the world's finest example of a distinctive type 

 of structure; that the glaciated plains of the northern United 

 States are among the widest in the world, by far the widest 

 of those equally accessible; also, that our coal and iron, gold 

 and silver, oil and gas, and numberless other valuable minerals 

 tempt curiosity and cupidity, as well as serious inquiry from 

 sea to sea. While the opportunities are unsurpassed, there 

 has been no dearth of genius to seize them; and while America 

 may still take lessons from Europe in mineralogy and perhaps 

 in petrography, the relation is reversed in other departments 

 and in the principles of the science, and leading European 

 geologists take frequent field lessons on this side of the 

 Atlantic. 



Hardly a serious question as to the eternal fixity of species 

 and genera and orders had been raised in scientific minds before 

 1848, save by Lamarck and a few other quasi visionaries, 

 while conservative leaders Hke Agassiz in Switzerland, Cuvier 

 in France, and Owen in England were so deeply grounded in 

 the philosophy of fixity as only to be the more firmly set by 

 each shock of new discovery. Just ten years later Darwin 

 and Wallace independently announced the inconstancy of 

 species and the derivation of organic units through successive 



Vol. 7—3 



