158 Kansas Academy of Science. 



Again (p. 132) : 



"Slow though the process of selection may be, if feeble man can do 

 much by artificial selection, I can see no limit to the amount of change, to 

 the beauty and complexity of the coadaptations between all organic beings 

 and their conditions of life which may have been effected in the long course 

 of time through nature's power of selection, that is, by the survival of the 

 fittest. . . . Natural selection acts solely through the preservation of 

 variations in some way advantageous, and which consequently endured." 



Again (p. 164) : 



"Variability is generally related to the conditions of life to which each 

 species has been exposed during several successive generations." 



While the fundamental principle thus brought out and elabo- 

 rated in "The Origin of Species" revolutionized science and still re- 

 mains unassailable as a principle, much criticism has arisen of the 

 sweeping application that Darwin made of it during the half cen- 

 tury since its promulgation. The application of the idea of natu- 

 ral selection to all kinds of variations is undoubtedly a weakness 

 of the great discoverer. Darwin cites and discusses many objec- 

 tions that were raised in his day, and did not overthrow them all 

 by any means. Other objections have arisen since, so that to-day 

 natural selection and slow modification stands only as one of sev- 

 eral methods by which species may have arisen. 



One of the most important of these opposing ideas is that of 

 the sudden and spontaneous arising of species, proposed by Prof. 

 Hugo De Vries, of Amsterdam. It is undoubtedly true that the 

 discovery and demonstration of the principle of mutations in the 

 formation of species and varieties of plants by Hugo De Vries, is 

 one of the most brilliant achievements in the history of evolution 

 since the publication of Darwin's "Origin of Species." Its recent 

 promulgation has thrown a flood of light upon many puzzling and 

 obscure questions, and has aided materially in the solution of some 

 intricate problems in the science of biology. Of course there is 

 danger of carrying it too far in its application, like all revolution- 

 ary discoveries, for after all it only supplements natural selection 

 and assists in solving problems that that great principle could not 

 account for. It is a source of wonder to later scientists that Dar- 

 win, with all his observations and great insight into the workings 

 of nature, should have failed to perceive the idea of sudden muta- 

 tions, and held it as an inviolable principle that all changes of 

 structure were due to very gradual alterations, the result of natural 

 selection. 



So it remained for the astute mind of De Vries to perceive that 

 sudden changes of structure were possible, and under certain con- 



