14 Dr Harvey's Observations on the 



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. If so, we are warranted in ascrib- 

 ing the same character to the annual growths of tree-plants 

 emanating from their buds, and in inferring that the succes- 

 sion of them from year to year, as congregated together and 

 constituting a tree, may equally go on for ever. 



The only difference, in fact, between a tree-plant and the 

 potato-plant, lies in the situation of their respective stems, 

 in the changes which these and their roots respectively 

 undergo after losing their vitality, and in the habitudes of 

 their respective offspring ; the stems of the one being above, 

 those of the other under ground ; the dead stems and roots of 

 the one continuing undecomposed and persistent for years or 

 ages, those of the other decaying early the following year, 

 when planted or left in the ground, and passing away ; the 

 offspring of the one growing together, and as parasites, on 

 the persistent dead remains of their parent, those of the other 

 striking down singly and separately into the soil, and having 

 no connection with any portion of their parents, the residue 

 of which has, in fact, ere now wholly disappeared, and no- 

 thing remaining around which, as a common centre, and a 

 mechanical support, they could grow as parasites. Had it 

 suited the purposes, immediate and remote, which the Author 

 of Nature had in view in giving them existence, we might 

 have had the respective peculiarities in the economy of the 

 plants completely reversed, — the potato-plant and its progeny 

 growing together and parasitically, and forming by their 

 aggregation a true potato-tree, fantastic, doubtless, in its 

 aspect, but possessing, as a whole, the same individuality 

 which common opinion ascribes to an ordinary tree, and the 

 separate plants being regarded and spoken of merely as an- 

 nual growths ; the tree-plants, on the contrary, growing and 

 extending themselves year by year as distinct and separate 

 individuals, and the so-called annual growths being looked 

 upon as perfect and independent plants. 



Reverting, now, to what takes place in trees, the processes 

 of grafting, of budding, and of slipping, seem to me to furnish 



