Selection mid Mutation. 13 



lated a vast storehouse of facts and observations; hut 

 our estimation of the importance and significance of the 

 individual facts themselves has undergone a change. 

 Moreover many new observations have been made which 

 place the results obtained by breeders in a new light. 



Breeders with few exceptions do not work in the 

 service of science ; and most of them take very little inter- 

 est in the purely scientific aspect of their work. They do 

 not make the general plan of their experiments as simple 

 as possible in the hope of finding a rational explanation. 

 On the contrary, as a rule, they prefer complex con- 

 ditions especially where their efforts are directed to the 

 production of new varieties. For the more numerous the 

 factors the greater the expectation of getting something 

 new and good. On the other hand scientific experiments 

 on variability should, where possible, be free from the 

 results of hybridization. But crosses are usually much 

 more important to the breeder than pure races, and only 

 in quite special cases has he the occasion to exclude 

 crossing with the utmost care. Although mutations are 

 often of much greater value to him than individual varia- 

 tions he usuallv treats them both after the same fashion 

 and often does not even distinguish between them. 



Moreover a systematic record of the culture, of the 

 kind that is absolutely essential to work with a scientific 

 object is not kept by breeders. It would cost far too 

 much time and labor. The only records that are kept 

 by most breeders are those which are necessary for the 

 compilation of their catalogues. And if after a few 

 years a new form proves to be something particularly 

 good, its history is written, as I have been personally in- 

 formed by one of the most distinguished breeders, partly 

 from the information in the older catalogues and partly 



