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XXII. On the Means of Prolonging the Duration of valuable 

 Varieties of Fruits, By Thomas Andrew Knight, Esq.FM.S. 

 President. 



Read May 3, 1831. 



Th e fact, that all trees of the same variety of fruit, where each 

 tree partakes necessarily of one common life, are in their habits 

 strongly connected with those of the first original tree of the va- 

 riety, is, I think, placed beyond the reach of controversy. None can 

 be made to produce blossoms, or fruit, till the original tree has 

 attained its age of puberty ; and under our ordinary modes of pro- 

 pagation by grafts, and buds, all become subject, within no very 

 distant period, to the debilities and diseases of old age. It is there- 

 fore desirable that the planter should know at what periods of their 

 existence varieties of fruits are most productive and eligible ; and 

 by what means (if any exist) the deterioration of valuable varieties 

 may be prevented or retarded. I was formerly inclined to believe 

 that grafts taken from very young seedling trees, as soon as the 

 qualities of their produce could be known, would shew more dispo- 

 sition to grow, than to produce fruit, and I had previously satisfied 

 myself that the blossoms of old and debilitated varieties of fruits 

 were extremely impatient of cold, and unfavourable weather ; and I 

 was thence led to infer that each variety possessed its greatest value 

 in its middle age. But subsequent experiment and observation have 

 compelled me to draw a different conclusion, and I believe that in 

 vegetable, as in animal life, the most prolific period is that which 

 immediately succeeds the age of puberty. 



I have made a good many experiments with a view of ascertain- 



