222 The University of CaliJor7iia Magazine. 



in it. He did not meet Hall, if I remember correctly, until 

 some time after he had become a regular student under Agas- 

 siz; and it can hardly be supposed that Hall's enthusiasm, 

 great as it is said to have been, could have been in itself a 

 greater winning force than Agassiz's. 



Strongly as biological phenomena appealed to his mind, he 

 must have found something in geology that attracted him still 

 more. Without presuming to have recognized positively and 

 fully what that something was, I believe we can detect at 

 least a part of it. 



I think we may say that the science of organisms did in. 

 deed appeal to him more than any other; but for him the 

 earth was an organism. It had a beginning in a simple, hom- 

 ogeneous state; it has undergone a continuous, orderly devel- 

 opment in time through the operation of its resident forces; it 

 will have an end. 



The contemplation oi forces ^x\6. processes was to him the thing 

 of supreme interest everywhere. In the biological province, it 

 was not the structure of the eye, but its mode of working and 

 its evolution that engaged his attention. It was not the his- 

 tology of the liver, but its glycogenic function that interested 

 him; not wing anatomy, but the flight of birds was it that he 

 found delight in studying. 



So in geology it was not the structure of mountains, but the 

 way they were built; not the composition of ore deposits, but 

 the method of their formation that he thought upon with such 

 zeal and pleasure and acumen. 



Now, the earth being for him an organism, because it is the 

 mightiest of all organisms, it attracted him more than any 

 other. 



His mind could not be satisfied with generalizations about 

 nature until they had reached out to its uttermost limits, and 

 in the infinite time of geology and the immensity of earth- 

 developing forces, he found room for the unhampered play of 

 his scientific imagination and unexcelled powers of general- 

 ization, that he did not find in biology. 



