ON FACT VS. THEORY 



"And that is why those who had devoted their 

 lifetimes to counting stamens and classifying 

 shapes told me, through their writings, that a cross 

 might be made within species, but never between 

 species; that is wliy 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 scores of times, that type of scientist 

 lost interest in rule making and went back to 

 stamen counting." 



***** 



To realize the point more clearly, let us observe 

 for a moment the common tomato — which belongs 

 to that large division of plants, the nightshade 

 family. 



Just as the rose family includes not only the 

 rose, but the apple and the blackberry and 

 sixty-two other plants, so the nightshade 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 containing 

 many eggs. 



These structural similarities in the plants of 



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