FUNCTIONS OF PLANTS. 35 



number of years to produce blossoms. Sometimes blossoms are produced, 

 which from defect, or want of vigour, prove abortive ; and when this is the 

 case, by removing from the plant all the blossom-buds before they expand, 

 for one or more years in succession, more vigorous blossoms will be pro- 

 duced, and the production of fruit ensured. This is the reason why on fruit 

 trees, a defective crop is generally succeeded by an abundant one, and the 

 contrary ; and why double-blossomed trees or herbs, which yield no fruit, 

 produce abundance of blossoms every year. 



129. The sexes consist of the stamens and pistils, of each of which there 

 are one or several, and often a great many in every flower. The use of the 

 stamens is to fertilise the rudimentary seeds which are contained in the 

 germen, or lower part of the pistillum. Fertilisation is effected by the pollen 

 of the anther applied to the stigma on the summit of the pistillum, hi conse- 

 quence of which an embryo plant, or ovulum (100), is generated in the 

 ovarium. In general the pistil of every flower is fertilised by pollen from the 

 stamens of the same flower ; but it occasionally happens in nature by the 

 action of bees or other insects, and in gardens by the instrumentality of man, 

 that the stigma of the flower of one species is fertilised by the pollen of the 

 flower of another species. The conditions of success are, for the most part, 

 that the two species should, at least, belong to the same genus, and in this 

 case the produce is said to be a hybrid. When it is effected by two varieties 

 of the same species, the plants produced are said to be crossbreds. The 

 latter generally produce fertile seed, but the former only sometimes. 



130. The fruit succeeds to the flower, the germen or base of the pistillum 

 growing and increasing in size, after the floral envelopes and the stamens 

 have decayed and dropped off. In some cases, the calyx is retained till the 

 fruit is ripe, (but without increasing hi size,) when the fruit is said to be 

 inferior ; as in the Apple, where the remains of the calyx form what is called 

 the eye, in the upper part of the fruit : whereas in the Peach, and all supe- 

 rior fruits, only the upper part of the pistillum is seen in that position. The 

 superior fruit adheres to the shoot on which it grows by the base of the 

 pistillum alone, while the inferior fruit adheres to it by the base of the entire 

 flower. For this reason inferior fruits are supposed to be less likely to drop 

 off in consequence of frost during the blossoming season, or other adverse 

 causes, than superior fruits ; and hence, other circumstances being the same, 

 a crop of Apples, of Pears, Quinces, Haws, Hips, Medlars, Currants, Goose- 

 berries, Melons, and Cucumbers, ought to be more certain than a crop of 

 Strawberries, Raspberries, Peaches, Plums, Apricots, Cherries, Grapes, or 

 Figs. 



131. So long as the fruit is green, it possesses to a certain extent the phy- 

 siological action of a leaf, and decomposes carbonic acid under the influence of 

 light ; but as soon as it begins to ripen, this action ceases, and the fruit is 

 wholly nourished by the sap elaborated by the leaves. Thus the fruit has, 

 in common vrith the leaves, the power of elaborating sap, and also the power 

 of attracting sap from the surrounding parts. Hence we see that where a 

 number of fruits are growing together, one or more of them attract the sap 

 or nutriment from all the rest, which in consequence drop off. As the food 

 of the fruit is prepared by the leaves under the influence of solar light, it 

 follows that the excellence of the fruit will depend chiefly on the excellence 

 of the leaves ; and that if the latter are not sufficiently developed, or not duly 

 exposed to the action of the sun's rays, or placed at too great a distance from 



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