56 GENERAL PRINCIPLES. 



they had received their due share of nutriment, fail in 

 attaining the proper condition, and produce only rosettes 

 of leaves. During the unfruitful season, immense quan- 

 tities of fruit-buds are again brought forward, and the 

 year following, the tree is overloaded ; so it proceeds in 

 regular alternation. 



This is never experienced in trees regularly pruned, and 

 may be remedied by thinning out the crop in bearing 

 years, leaving on but a reasonable amount, that will not 

 exhaust the tree. The bearing years have been complete- 

 ly reversed by removing the blossom-buds, or fruits, on 

 the bearing year. 



SECTION 7. THE FRUIT. 



1st. Character of the Fruit. As soon as the ovules are 

 impregnated, the ovary begins to swell ; the petals,stamens, 

 and other parts of the flower fall off, and we then say the 

 fruit is "set" As a fruit-bud is but a transformed leaf-bud, 

 a fruit occupies the same relative connection with the tree 

 as a branch ; it attracts food from the stem and the atmos- 

 phere in the same manner, and performs all the same func- 

 tions, except that it does not, like the leaf, return anything 

 to the tree, but appropriates all to its own use ; and this 

 is the reason, as we have before remarked, that trees hav- 

 ing borne a heavy crop of fruit one season, are less fruitful 

 the next this is the case only with fruits, as the apple 

 and pear, that require nearly the whole season to mature 

 them. Cherries and other fruits, that mature in a shorter 

 period, and that draw more lightly on the juices of the 

 tree, do not produce this exhaustion, and consequently 

 bear year after year uninterruptedly. 



2d. Classification. In some fruits, as the apple, for in- 

 stance, the fruit appears to be formed below, or at the base 

 of the calyx ; structurally, it is properly regarded as an 

 adhesion of the greater part of the calyx to the ovary ; 



