Chap. XI. OF THE CHAPTER. 441 



As wild plants are so rarely liable to bud-variation, whilst 

 highly cultivated plants long propagated by artificial means 

 have yielded many varieties by this form of reproduction, we 

 are led through a series such as the following, — namely, all 

 the eyes in the same tuber of the potato varying in the same 

 manner, — all the fruit on a purple plum-tree suddenly 

 becoming yellow, — all the fruit on a double-flowered almond 

 suddenly becoming peach like, — all the buds on grafted trees 

 being in a very slight degree affected by the stock on which 

 they have been worked, — all the flowers on a transplanted 

 heartsease changing for a time in colour, size, and shape, — we 

 are led by such a series to look at every case of bud- variation 

 as the direct result of the conditions of life to which the 

 plant has been exposed. On the other hand, plants ot the 

 same variety may be cultivated in two adjoining beds, appa- 

 rently under exactly the same conditions, and those in the one 

 bed, as Carriere insists, 158 will produce many bud-variations, 

 and those in the other not a single one. Again, if we look to 

 such cases as that of a peach-tree which, after having been cul- 

 tivated by tens of thousands during many years in many 

 countries, and after having annually produced millions of 

 buds, all of which have apparently been exposed to precisely 

 the same conditions, yet at last suddenly produces a single 

 bud with its whole character greatly transformed, we are 

 driven to the conclusion that the transformation stands in 

 no direct relation to the conditions of life. 



We have seen that varieties produced from seeds and from 

 buds resemble each other so closely in general appearance 

 that they cannot be distinguished. - Just as certain species 

 and groups of species, when propagated by seed, are more 

 variable than other species or genera, so it is in the case of 

 certain bud- varieties. Thus, the Queen of England Chry- 

 santhemum has produced by this latter process no less than 

 six, and Rollisson's Unique Pelargonium four distinct 

 varieties ; moss-roses have also produced several other moss- 

 roses. The Rosaceaa have varied by buds more than any 

 other group of plants ; but this may be in large part due 

 to so many members having been long cultivated; but 



158 i Production des Varietes,' pp. 58, 70. 

 20 



