CHAPTER XXVI 



THEORY OF PLANT BREEDING 



THE practical breeder of plants proceeds doggedly with 

 his experiments, yearly launching on the world new and, 

 it is to be hoped, distinctly lucrative varieties. 



All the time there is surging around him furious con- 

 troversies which are shattering and overwhelming the 

 very basic principles upon which the whole of his work 

 depends. Now it is a high tide of Weissmannism, then a 

 raging sea of Mendelism, which is followed by foaming 

 waves of the theory of Mutants, and so on indefinitely. 



He knows nothing of these angry storms, and would 

 not very much care about any of those proofs and deduc- 

 tions and denials which so abundantly distinguish every 

 new point of view. 



It is of course abundantly clear from every breeder's 

 experience that acquired characters are in some way or 

 other inherited. One has only to refer to those Alpine 

 larches (see p. 291), to Klebs' experiments (p. 292), and 

 to all ordinary gardening experience. 



Desert plants are adapted in almost every one of their 

 characters to the necessities of the desert. It is an ex- 

 tremely difficult matter to grow them in an ordinary 

 British garden. But if a very skilled gardener can 

 manage to raise a few out of many seeds, the results are 

 very interesting. They retain some of the desert char- 

 acteristics, but in a modified way. They are neither so 

 hairy nor so woody, but yet show quite well the struggle 

 which is going on between heredity and environment. 

 They are trying to adapt themselves to the new con- 

 ditions, but retain many desert characters. 



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