344 LUTHER BURBANK 



merit of adding a certain measure of tangibility 

 to the mental picture of the actual processes in- 

 volved in the hereditary transmission of traits 

 through which the white blackberry was devel- 

 oped. And there can be no question of the con- 

 venience of these terms and of their value in aid- 

 ing to conjure up such a picture, provided it be 

 not supposed that the presentation of such a 

 formula is to clarify all the mysteries of heredity 

 and to do away with the necessity in the 

 future — as some misguided enthusiasts have as- 

 sumed — of laborious and patient experiments 

 akin to those through which the triumphs of 

 the plant developer have been achieved in the 

 past. 



In a word, the Mendelian formulas, if ac- 

 cepted at their true valuation and for their real 

 purpose, may be regarded as placing new and 

 valuable tools in the hands of the plant experi- 

 menter, just as did the formula of natural selec- 

 tion as put forward by Darwin; but we must 

 in one case as in the other guard against imagin- 

 ing that the phrasing of a formula may properly 

 take the place of the practical observation of 

 matters of fact. 



Bearing this caution in mind, let us note the 

 changed terminology in which the Mendelian of 

 to-day interprets the observed facts of the de- 



