Xo. 506] 



DAEU'IX AXD MUTATION THEORY 



good evidence that cultivated plants and animals are more 

 subject to wide and abrupt variations than are those 

 living under natural conditions. On this point Professor 

 De Vries remarks that "it is not proved, nor even prob- 

 able, that cultivated plants are intrinsically more variable 

 than their wild prototypes." 4 As to distinct mutations, 

 we must remember that plants and animals preserved 

 and nurtured by man are constantly under the eyes of 

 many thousands of pecuniarily interested observers, 

 while those in a state of nature are closely studied by but 

 a handful of scientific investigators. We must also 

 remember that it is only within a few years that a small 

 fraction of these men of science have been led to look for 

 cases of mutation, while all gardeners, farmers and 

 breeders have had the inducement of financial profit to 

 watch for marked variations among their stock and to 

 preserve such variations if desirable. The naturalists 

 specially interested in evolutionary questions are exceed- 

 ingly few in number, but their field of research is im- 

 mensely extended and varied. The number of those who 

 have raised animals and plants for gain, however, has 

 always been large, though the number of forms which they 

 have been called upon to consider have been relatively 

 few. The two fields have consequently had exceedingly 

 different degrees of scrutiny. But since De Vries and 

 others opened up the subject an astonishing number of 

 clearly proven cases of mutation have been discovered 

 in very various classes of organisms, just as numerous 

 paleontological evidences of evolution have been brought 

 to light as a consequence of Darwin's turning men's 

 minds in that direction. 



As I have already intimated. Mr. Darwin undoubtedly 

 dealt with numerous cases of mutation among domesti- 

 cated animals and plants, and thev gave him little or no 

 intellectual disquietude. In his work on "Animals and 

 Plants Under Domestication" he gives a long catalogue 

 of "spontaneous variations" or "sports," many of which 



