LETTER VIII. 71 



its kind annually in endless perpetuity from buds, I 

 will adduce further proof. And, in the first instance, 

 I shall refer you to the potato-plant, — a plant which, 

 though it never grows up into a tree, contains all the 

 elements of a tree, and is equally perennial in its 

 duration as any tree. 



8. The tuber familiarly known as the potato bears 

 a very close resemblance to the yearling shoot or stem 

 of a tree. It is confessedly of the same nature with 

 such a shoot. It is, in fact, an underground stem, and 

 consists of a layer of bark and a layer of woody tissue 

 enclosing a mass of pith, and furnished with buds. 

 This underground stem, when planted in Spring, sends 

 out from each of its buds a growth, which has a stem 

 (underground) and roots and leaves and flowers, and 

 which forms buds and seeds — structures that are the 

 exact counterparts of those composing the growths 

 that proceed from the buds of trees. Does any one 

 ever doubt that the annual potato-growths which he 

 sees in the fields are perfect and independent plants ? 

 Does any one doubt that from the buds alone, without 

 ever having recourse to seed, a succession of such 

 potato- plants may be kept up from year to year for 

 ever ? I apprehend not. 



9. The tree-plant and the potato-plant, each growing 

 from buds after its kind, are in fact identical in con- 

 stitution and structure. The only difference between 

 them lies in the situation of their respective stems, — in 



