ON FACT VS. THEORY 



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, 

 however, but at the seventy-five plants themselves, 

 then, and only then, could we fully realize the 

 wonders which environment, toying with that 

 common heredity within the plant, has wrought. 



We should see, among the seventy-five brothers 

 and sisters of that family if they were spread 

 before us, the poisonous bitter-sweet, and the 

 humble but indispensable potato; the egg plant 

 and the Jerusalem cherry; the horse nettle and the 

 jimson weed; the tobacco plant and the beautiful 

 petunia; and the tomato itself. 



We should see seventy-five plants with original 

 structural similarities, yet differing, in every other 

 way, as night differs from day; and we should be 

 able to trace, if we observed closely enough, the 

 points at which, in the history of this family, new 

 environment, oft repeated, has hardened into 

 heredity, subject to the call of still newer environ- 

 ment, which has not been lacking to bring it out; 

 we should be able to trace out, by easy stages, 

 why one branch ran to the poisonous bitter-sweet, 

 another to the potato with its food product below 

 the ground, another to the tomato with its 

 tempting fruit displayed on vines above; another 



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