Improvements Made in Plants by Man 443 



out the constituent methods and discuss each by itself. But 

 thereby I have given the matter an aspect of simplicity which 

 it is far from deserving, for not only are the methods inextricably 

 interconnected, but practical difficulties of innumerable sorts 

 interpose large obstacles to their successful operation. Thus, 

 I have spoken of plant breeding as it would be conducted when a 

 matter of dehberate intention on the part of a worker with a 

 definite idea in his mind. This, however, it rarely is except in the 

 case of modern scientific plant-breeders, wealthy amateurs, or a 

 few far-sighted conmiercial dealers in horticultural novelties, of 

 whom the most conspicuous by far is Luther Burbank, well known 

 of late to the readers of periodical literature. iVs a matter of fact, 

 most plant improvement has been made on the spur of the mo- 

 ment, by the selection of something which happened to please 

 the fancy, or appeal to the sense of profit, of gardener or farmer, 

 who of course has always sought to propagate from the plants he 

 considers his "best. " But the art of horticulture is long, and the 

 life of man is short, and fancies change, and things that are profit- 

 able vary; wherefore improvement has been spasmodic, and 

 along most devious courses. Nor are horticultural productions 

 wholly stable when once secured, for varieties, even when true to 

 their good character for a time, tend strongly to revert or merge 

 off or "wear out" to less desirable kinds, though there is perhaps 

 a difference between mutations which are permanently stable, and 

 the results of the selection of small variations, which are unstable. 

 Furthermore, hybridization, especially for the combining of 

 features from different races into one, is by no means so simple as 

 its theory implies, but a process distinguished by innumerable 

 failures, and requiring a persistence and skill that few breeders 

 command. The potentiaHties of improvement, indeed, have a 

 vast burden of practical troubles to carry; and it is this which 

 makes its progress so halting and laborious. 



It is evident that in his improvement of plants, man never 

 creates, except by a figure of speech, but only directs. He cannot 



