246 LUTHER BURBANK 



between species; that is why when I did make a 

 cross between species they looked no further into 

 the truth, but simply moved up a notch, and said, 

 "Very well, but you cannot make a cross between 

 genera"; that is why, when I did that very thing, 

 not once, but several times, that type of scientist 

 lost interest in rule making and went back to 

 stamen counting. 



To realize the point more clearly, let us ob- 

 serve for a moment the common tomato which 

 belongs to that large division of plants, the 

 Solanum family. 



Just as the rose family includes not only the 

 rose, but the apple and the blackberry and hun- 

 dreds of other plants, so the Solanum family 

 includes seventy-five genera and more than 

 eighteen hundred species. 



The classification is built around structural 

 facts, such as that plants of this family originally 

 had alternate leaves with five stamens and a two- 

 celled ovary, or egg chamber, each cell contain- 

 ing many eggs. 



These structural similarities in the plants of 

 this family trace back to a common parentage 

 and fully justify the classification of these 

 seventy-five genera in a single family. 



If we were to look not at the structure, how- 

 ever, but at the seventy-five genera themselves 



