PROFESSOR RILEY'S OBITUARY 335 



* Riley was from the first a pronounced evolutionist. His 

 philosophic breadth and his thoughtful nature and grasp of the 

 higher truths of biology are well brought out in his address on 

 <l The Causes of Variation in Organic Forms," as Vice- President, 

 before the biological section of the American Association for 

 the Advancement of Science in 1888. He was a moderate 

 Darwinian, and leaned, like other American naturalists, rather 

 to Neo-Lamarckism. He says : " I have always had a feeling, 

 and it grows on me with increasing experience, that the weak 

 features of Darwinism and, hence, of natural selection, are his 

 insistence (i) on the necessity of slight modification ; (2) on the 

 length of time required for the accumulation of modifications, 

 and (3) on the absolute utility of the modified structure." Riley, 

 from his extended experience as a biologist, was led to ascribe 

 much influence to the agency of external conditions, remarking, 

 in his address : u Indeed, no one can well study organic life, 

 especially in its lower manifestations, without being impressed 

 with the great power of the environment." He thus contrasts 

 Darwinism and Lamarckism : " Darwinism assumes essential 

 ignorance of the causes of variation and is based on the inherent 

 tendency thereto in the offspring. Lamarckism, on the contrary, 

 recognizes in use and disuse, desire and the physical environ- 

 ment, immediate causes of variation affecting the individual and 

 transmitted to the offspring, in which it may be intensified again 

 both by inheritance and further individual modification." ' 



4 " Evolution shows that man is governed by the same laws as 

 other animals." u Evolution reveals a past which disarms doubt 

 and leaves the future open with promise unceasing purpose 

 progress from lower to higher. It promises higher and higher 

 intellectual and ethical attainment, both for the individual and 

 the race. It shows the power of God in what is universal, not 

 in the specific ; in the laws of nature, not in departure from 

 them." ' 



