298 PRUIT OE MATURE PISTIL. 



they usually become so in the course of the second or third generation. 

 Herbert mentions instances of hybrid Narcissi, from which he at- 

 tempted in vain to obtain seed. The cause of this sterility has not 

 been determined. Some have referred it to an alteration in the 

 pollen. Hybrids may be fertilised, however, by the pollen taken 

 from one of the parents, and then the ofispring assumes more or less 

 the characters of that parent. 



Hybrids are rarely produced naturally, as the stigma is more likely 

 to be affected by the pollen of plants of its own species than by that 

 of other species. In dicecious plants, however, this is not the case, 

 and hence the reason, probably, of the numerous co-called species of 

 Willows. Hybrids are constantly produced artificially, with the view 

 of obtaining choice flowers and fruits, the plants being propagated 

 afterwards by cuttings. In this way many beautiful Eoses, Azaleas, 

 Rhododendrons, Pansies, Cactuses, Pelargoniums, Fuchsias, Calceo- 

 larias, Narcissuses, etc., have been obtained. By this process of 

 inoculation, and carefully selecting the parents, gardeners are enabled 

 to increase the size of the flowers, to improve their colour, to render 

 tender plants hardy, and to heighten the flavour of fruits. Herbert 

 thinks, from what he saw in Amary Hides, that in hybrids the flowers 

 and organs of reproduction partake of the characters of the female 

 parent, while the foliage and habit, or the organs of vegetation, re- 

 semble the male. 



G.— Fruit, or the Pistil arrived at Maturity. 



After fertilisation, various changes take place in the parts of the 

 flower. Those more immediately concerned in the process, the anther 

 and stigma, rapidly wither and decay, whUe the filaments and style 

 often remain for some time ; the floral envelopes also become dry, the 

 petals fall, and the sepals are either deciduous, or remain persistent in 

 an altered form ; the ovary becomes enlarged, forming the pericarp 

 (•s-Ef /', around, and %af ots, fruit) ; and the ovules are developed as the 

 seeds containing the embryo-plant. The term fruit is strictly applied 

 to the mature pistil or ovary, with the seeds in its interior. But it 

 often includes other parts of the flower, such as the bracts and floral 

 envelopes. Thus, the fruit of the Hazel and Oak consists of the 

 ovary and bracts and calyx combined ; that of the Apple, Pear, and 

 Gooseberry, of the ovary and calyx ; and that of the Pine-apple, of 

 the ovaries and floral envelopes of several flowers combined. Fruits 

 formed by the ovaries alone, as the Plum and the Grape, seem to be 

 more liable to drop off and suffer from unfavourable weather, than 

 those which have the calyx attached, as the Gooseberry, the Melon, 

 and the Apple. 



In general, the fruit is not ripened unless fertilisation has been 



