APPENDIX. 



REMARKS ON THE DURATION OF VARIETIES OF FRUIT 

 TREES. 



IT was, for a long time, the popular notion that when a good 

 variety of fruit was once originated from seed, it might be con- 

 tinued by grafting and budding, for ever, or, at least, as some 

 old parchment deeds pithily gave tenure of land " as long as 

 grass grows, and water runs." 



About fourteen years ago, however, Thomas Andrew Knight, 

 the distinguished President of the Horticultural Society of 

 London, published an Essay in its Transactions, tending entirely 

 to overthrow this opinion, and to establish the doctrine that all 

 varieties are of very limited duration. 



The theory advanced by Mr. Knight is as follows : All the 

 constitutional vigour or properties possessed by any variety of 

 fruit are shared at the same time by all the plants that can be 

 made from the buds of that variety, whether by grafting, bud- 

 ding, or other modes of propagating. In simpler terms, all the 

 plants or trees of any particular kind of pear or apple being 

 only parts of one original tree, itself of limited duration, it 

 follows, as the parent tree dies, all the others must soon after 

 die also. " No trees, of any variety," to use his own words, 

 " can be made to produce blossom or fruit till the original tree 

 of that variety has attained the age of puberty ;* and, under 

 ordinary modes of propagation, by grafts and buds, all become 

 subject, at no very distant period, to the debilities and diseases 

 of old age." 



It is remarkable that such a theory as this should have been 

 offered by Mr. Knight, to whose careful investigations the 



* This part of the doctrine has of late been most distinctly refuted, and 

 any one may repeat the experiment. Seedling fruit trees, it is well- 

 known, are usually several years before they produce fruit. But if a graft 

 is inserted on a bearing tree, and after it makes one season's fair growth, 

 the grafted shoot is bent directly down and tied there, with its point to 

 the stock below, it will, the next season the sap being checked produce 

 flower-buds, and begin to bear, long before the rarent tree. 



