ON THE TOMATO 



were obviously due to the lack of their natural 

 protective soil covering. 



But the fact that the vine, handicapped by lack 

 of roots of its own kind, should have been able to 

 transform leaf buds into tuber-growing aerial 

 rootlets furnishes an interesting lesson in the meta- 

 morphosis of parts. How the great poet Goethe, 

 who first expounded the theory of metamorphosis 

 of parts, and clearly recognized the fundamental 

 unity of stem and leaf and flower, would have 

 enjoyed the viewing of a spectacle like that! 

 Questions of Sap Hybridism 



And for the modern plant developer, the 

 strange compound vines have no less interest, for 

 they suggest a number of questions that are much 

 easier to ask than to answer. 



How, for example, was the leaf system of the 

 potato that grew the aerial tubers to know that 

 tubers were not being formed about its roots in 

 the ordinary way? It did know this, obviously, 

 else it would not have adopted the unprecedented 

 expedient of growing tubers in the air. 



It is easy to speculate, and to suggest, for 

 example, that the potato plant producing an excess 

 of sugar and starch in the usual way, must find 

 some place to deposit it, and that as no demand 

 came from the roots, the only available buds were 

 made to do vicarious service. But the explanation 



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