THE TOMATO 179 



It follows, then, that the tomato plant, even 

 though its source of supply was the root system 

 of a potato, merely gained from these roots 

 part of the raw inorganic materials with which 

 its leaves were to manufacture the special 

 compounds that go to make up a tomato. 

 Inasmuch as the tomato leaves were them- 

 selves unmodified, there was no reason why 

 their product, the tomato, should be greatly 

 modified. 



In receiving its supply of raw material from 

 a foreign root, the tomato top was in no dif- 

 ferent condition from the ordinary cions in a 

 fruit orchard, which, as we have seen, are habitu- 

 ally grafted on roots or branches of a foreign 

 species. 



But the case of the potato tubers is obviously 

 quite different. Their substance is made up of 

 material that came originally, to be sure, in part 

 from material gathered by potato roots ; but this 

 material had traveled up to the leaves of the 

 tomato plant and had there been transformed; 

 so when it returned to be deposited and form 

 tubers it was a tomato compound and not a 

 potato compound. 



It was not absolutely different in material 

 from the material of the ordinary potato, be- 

 cause the tomato and potato are cousins. 



