ARE OWN-ROOTED PLANTS BETTER ? 87 



domestication, or, in other words, unnaturalness, may be 

 sometimes a stimulus, it is not necessarily so. Cultivation 

 differs from natural conditions more in degree than in kind. 

 Or, as Darwin writes, "Man may be said to have been 

 trying an experiment on a gigantic scale," and "it is an 

 experiment which nature during the long lapse of time 

 has incessantly tried." 



3 It is said that own-rooted plants are better than fos- 

 ter-rooted ones. This is merely an assumption, and yet it 

 has been held with dogmatic positiveness by many writers. 

 If mere unnaturalness, that is, rarity or lack of occurrence 

 in nature, is no proof of perniciousness, as has been 

 shown, then this statement admits of argument just as 

 much as any other proposition. And surely at this day 

 we should test such statements by direct evidence rather 

 than by a priori convictions. The citation of any number 

 of instances of the ill-effects of graftage is no proof that 

 own-rooted plants are necessarily better, if there should 

 still remain cases in which no injurious effects follow. 

 Now, if it is true that "own-rooted things are in all ways 

 infinitely better, healthier and longer-lived" than foster- 

 rooted plants, and if "grafted plants of all kinds are 

 open to all sorts of accidents and disaster," then the 

 proposition should admit of most abundant proof. The 

 subject may be analyzed by discussing the following 

 questions: a. Is the union always imperfect? b. Are 

 grafted plants less virile than own-rooted ones ? Are they 

 shorter lived? 



a. It is well known that the physical union between 

 cion and stock is often imperfect, and remains a point of 

 weakness throughout the life of a plant. But this is not 

 always true. There are scores of plants which make per- 

 fect physical unions with other plants of their own species, 

 or even with other species, and it follows that these, 

 alone, are the plants that should be grafted. The very 

 best proof which can be adduced that the union may be 

 physically perfect, is to be found in the micro-photograph 



