196 Mr. Knight on the Effects of Age upon Fruit Trees. 



thought them when he was a school-boy. Thatsome change may, 

 however, have taken place in our climate, owing to the opera- 

 tion of many concurrent causes, is not improbable, but not in 

 a degree equivalent to the effects produced. Any considera- 

 ble change of climate must also have affected alike the new 

 and the old varieties of fruits, and the decay of the latter alone 

 seems therefore to prove some constitutional change to have 

 taken place in those. 



If the leaf gradually fail to execute properly its office, a 

 progressive degree of debilit} r , preceding a state of disease and 

 decay, must necessarily follow ; and this I have noticed in 

 some moderately old varieties of the Apple and Pear. They 

 remain free from disease ; they blossom frequently, and some- 

 times freely; but they rarely afford much fruit; and their 

 recovery, from the exhausted state in which even a moderate 

 crop of fruit leaves them, is very slow. If this state be in- 

 duced, as I am well satisfied that it is, by the inefficient ope- 

 ration of the foliage, it becomes an interesting question at 

 what period of the age of each variety such defective opera- 

 tion commences. The observations which I have had oppor- 

 tunities of making, lead me to believe that it commences at 

 the period when the original tree becomes, according to the 

 ordinary course of nature, debilitated by age; and I suspect 

 that much the greater part of the varieties of fruit, of different 

 species, which are now named in the catalogues of nursery- 

 men, have already outlived the periods at which they best de- 

 served the attention of the planter. This remark I wish par- 

 ticularly to apply to the Peach and Nectarine; varieties of 

 which, of equal excellence and much superior vigour and 

 hardiness, may be easily obtained from seeds ripened in the 

 forcing-houses, if not upon the open walls, of our gardens. I 

 sent to you, in the last autumn, many new varieties of Necta- 

 rines raised in my Peach-house from seeds of the Elruge and 

 the pollen of the Early Violet Nectarine. They were the pro- 

 duce of buds inserted into the bearing branches of old Peach 

 and Nectarine trees growing upon my walls, the original 

 seedling trees not having been retained in my garden. 



Every attention was paid to make the fruit from which the 

 seeds were taken attain the highest state of perfection, and 

 the crop of fruit of the trees which bore them, and from which 

 the pollen was taken, was sacrificed almost wholly in the pre- 

 ceding season, that both those might be in the most efficient 

 and vigorous state ; and 1 preferred the forcing-house to the 

 open wall, that the wood and blossoms might attain the most 

 perfect state of maturity. Of the merits of the Nectarines you 

 received, I wish to decline giving an opinion; and I shall 



therefore 



