FLORAL ORGANS. 



229 



420. A pistil is distinguished into three parts ; namely, the 



OVARY (Fig. 264, a), the 

 hollow portion at the base 

 which contains the OVULES, 

 or bodies destined to be- 

 come seeds ; the STYLE (b ) , 

 or columnar prolongation 

 of the apex of the ova- 

 ry ; and the STIGMA (c), a 

 264 portion of the surface of 



the style denuded of epi- 

 dermis ; sometimes a mere point or a small knob 

 at the apex of the style, but often forming a sin- 

 gle or double line running down a part of its in- 

 ner face, and assuming a great diversity of ap- 

 pearance in different plants. 



421. All the organs of the flower are situated 

 on, or grow out of, the apex of the flower-stalk, 

 into which they are said, in botanical language, 



to be inserted, and which is called the TORUS, or RECEPTACLE. 

 This is the axis of the flower, to which the floral organs are at- 

 tached (just as leaves are to the stem) ; the calyx at its very base ; 

 the petals just within or above the calyx ; the stamens just within 

 the petals ; and the pistils within or above the stamens. 



422. Such is the structure of a complete and regular flower ; 

 which we take as the type, or standard of comparison. The calyx 

 and corolla are termed protecting organs. In the bud, they en- 

 velope the other parts : the calyx sometimes forms a covering 

 even for the fruit ; and when it retains its leaf-like texture and 

 color, it assimilates the sap of the plant with the evolution of 

 oxygen gas, in the same manner as do true leaves : the corolla 

 elaborates honey or other secretions, for the nourishment, as is 

 supposed, of the stamens and pistils. But neither the calyx nor 

 corolla is essential to a flower, one or both being not unfrequently 

 wanting. The stamens and pistils are, however, essential organs 



FIG. 263. A pistil of Crassula, like that of Fig. 261, but more magnified, and cut across 

 through the ovary, to show its cell, and the ovules it contains. At the summit of the style is 

 seen a somewhat papillose portion, destitute of epidermis, extending a little way down the in- 

 ner face : this is the stigma. 



FIG. 264. Vertical section of a pistil, showing the interior of its ovary, a, to one side of 

 which are attached numerous ovules, d: above is the style, b, tipped by the stigma, c. 



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