or THE FEUIT. 781 



plants make their appearance, which present characters of an 

 intermediate nature between two known species. 



3. Of the Feuit. — "When fertilization has been effected 

 (see p. 288), important changes take place in the pistil and 

 other organs of the flower, the result of which is the forma- 

 tion of the fruit. The calyx and corolla generally fall off, or if 

 persistent, they form no portion of the fruit, except when the 

 calyx is adherent, as in the Apple {fg. 705), when it necessarily 

 constitutes a part of the pericarp ; the style and stigma also 

 become dry, and either fall off, as in the majority of cases, or are 

 persistent, as in the Poppy and Anemone {fig. 686). The prin- 

 cipal alterations, however, take place in the wall of the ovary, 

 which usually becomes more or less swollen, and soon undergoes 

 important chemical changes, and forms the pericarp, either by 

 itself, or combined with the adherent calyx. Some pericarps, as 

 already noticed (p. 292), are fully developed without the fertili- 

 zation of the ovule, as those of many Oranges, Grapes, Bananas, 

 &e. The fruits thus formed, although frequently more valuable 

 than others for food, are useless for reproduction. 



The fruit in its growth attracts the food necessary for that 

 purpose from surrounding parts, hence, the fruiting of plants 

 requires for its successful accomplishment an accumulation of 

 nutrient matter, and is necessarily an exhaustive process. That 

 the reproductive processes, and especially the maturation of 

 the fruit, tend to exhaust the individual, is proved in various 

 ways. Thus, plants which fruit the same year in which they are 

 developed afterwards perish, from the exhaustion of nutrient 

 matter thus occasioned; and that such is the reason is proved 

 by the fact, that we can make annuals biennial or even perennial, 

 by plucking off the flower-buds as they are developed. Some 

 plants which only flower once require many years to accumulate 

 sufficient nourishment to support the processes of reproduction. 

 Such are the American Aloe and the Talipot Palm, both of which 

 live very many years before flowering, after which they die. 

 A bad fruit year is generally succeeded by a good one, and 

 vice versa, because in the former case an additional supply of 

 nutrient matter is stored up for the fruiting season, and in the 

 latter there is a diminished amount. Again, if a branch of an 

 unproductive tree have a ring of bark removed so as to prevent 

 the downward flow of the elaborated sap, its accumulation 

 above will cause the branch to bear much fruit. Pruning 

 depends for its success upon similar principles. In order to 

 obtain good fruit it is also necessary, not to allow too many to 

 come to perfection on the same plant. Other matters connected 

 with this exhaustion by fruiting have been already alluded to, 

 in speaking of Annual, Biennial, and Perennial Roots, at page 

 120. 



