92 VEGETABLE PHYSIOLOGY. 



VEGETABLE PHYSIOLOGY. 



ORGANS OF FRUCTIFICATION. 

 BY MR. JOHN TODD, DENTON GARDENS, NEAR GRANTHAM. 



The chief object of the growth of plants appears to be the maturation ot 

 seed in the end. in order that new individuals can be raised to supply- 

 he places of those whicli are necessarily appropriated to the sustenance 

 and necessities of innumerable races of animated beings, or swept away 

 by the inevitable consequences of old age, death, and decomposition. 

 Suckers, runners, and offsets are incidental modes of natural propaga- 

 tion ; chiefly, however, the unbroken succession of plants is due to their 

 capacity of giving birth to seeds. These are engendered in the 

 ovarium by tlie natural action of those delicate and beautiful organs 

 the stamens and pistils, whose ingenious construction and admirable 

 adaptation to the grand end in view are legitimate subjects for tlie in- 

 vestigation of the gardener, and well deserving his attentive study. 



It is only in tlie higlier grades of vegetable life that we find a sexual 

 apparatus designed exclusively for the generation of seed ; the repro- 

 duction of Cryptogamous plants is effected by a much less complicated 

 tliough no less efficient means. Ferns, and others of the more highly 

 developed Cryptogama, are multiplied by spores, produced in little 

 cases on the under surface of their leaves (fronds), which, wlien ripe, 

 split open, and allow tlie fructifying matter to escape. The repro- 

 duction of Fungi is still more simple, whilst the whole substance of the 

 lower forms of Algae seems to dissolve into myriads of minute gems, 

 eacli capable of giving birth to a being like its parent. 



In treating of the fructifying process in Phsenogamia, or Flowering 

 Plants, the structure of the flower will have to be considered. A 

 flower, when perfectly developed, is composed of the following parts — 

 calyx, corolla, stamens, and pistil ; and one or more of these parts are 

 present in every flower. Tlie calyx is the exterior portion of the 

 flower, and usually consists of one or more leaflets or sepals, serving as 

 an envelope and protection to tlie tender flower-bud, and very probably 

 yields to the flower a portion of elaborated food, both before and after 

 its expansion. In immediate contact with the calyx, and between it 

 and the stamens, we find the corolla the most conspicuous, and, it may 

 be added, interesting portion of the flower, for its varied tints and 

 agreeable fragrance have ever been a source of pleasing admiration. 

 Its brilliant colours and honied secretions serve as a decoy to innume- 

 rable tribes of insects, wiiicli alight upon its anthers and scatter the 

 fertilizing powder with their legs and wings, and thus assist in the 

 work of impregnation. Apart from this, the utility of the corolla 

 seems to be identical with that of the calyx, for, although it is absent 

 from many of the flowers, " yet, if removed from those possessing it 

 before impregnation is completed, fertilisation never takes place." 



Within the beautiful corolla are observed a number of delicate 

 filaments, mounted with orange, purple, or wiiitish-coloured bodies, 

 often so nicely poised as to be susceptible of the slightest breeze. 

 Tliese constitute the male system of a flower, and are called stamens. 

 The little objects crowning their filamentous (thread-like) portion are 



