236 



ESSENTIAL ORGANS — THE PISTIL. 



-ft'^ 



Fig. 406. i'lg. lUT. 



of the pistil may be seen by examining the flower of the double-flower- 

 ing Cherry. In it no fruit is produced, and the pistil consists of sessile 

 leaves (fig. 405), the limb of each being green and folded, with a 

 narrow prolongation upwards, s, as if from the 

 midrib, n, and ending in a thickened portion. 

 When the single-flowering Cherry is examined, 

 it is found that, in place of folded leaves, there 

 is a single body (figs. 406, 407), the lower part 

 of which is enlarged, forming the ovary, o, and 

 containing a single ovule, g, attached to its 

 walls, with a bundle of vessels, /«, entering 

 it, a cylindrical prolongation, t, forming the 

 style, and a terminal expansion, s, the stigma. 

 It will be seen that in this case two carpellary 

 Z'^" leaves have become succulent, and have united 

 together so as to form a compound pistil, with 

 a single cavity containing one seed. 



The Ovary then represents the limb or 

 lamina of the leaf, and is composed of cellular tissue with fibro-vascu- 

 lar bundles, and an epidermal covering. The cellular tissue, or paren- 

 chyma, often becomes much developed, as will be seen particularly 

 when fleshy fruits are considered. The outer epidermis corresponds 

 to the lower side of the leaf, exhibiting stomata, and sometimes hairs ; 

 the inner surface represents the upper side of the leaf, being usually 

 very delicate and pale, and forming a layer called sometimes epi- 

 thelium, which does not exhibit stomata. The vascular bundles cor- 

 respond with the veins of the leaf, and consist of spiral, annular, and 

 other vessels. 



The Style has usually a cylindrical form, consists of cellular and 

 vascular tissue, and when carefully examined is found to be traversed 

 by a narrow canal (fig. 407 c), in which there are some loose project- 

 ing cells (figs. 408, 409), forming what is called the conducting tissue. 

 A transverse section of the style of Crown Imperial (fig. 408) shows 

 three vascular bundles, v v v, corresponding to three styles which are 

 united into one, and loose cells, p, in the canal of the style. This 

 canal is bounded by cellular tissue (fig. 409, e c), traversed by spiral 

 vessels, v v, and in its interior, besides the loose cells, p p, there are, 

 especially at the period of fecundation, elongated tubes, //, which in 

 part fill up the canal. The name, conducting tissue, is given to that 

 found in the canSl of the style, on account of the part which it plays 

 in conveying the influence of the poUen to the ovules, as will be ex- 



Pig. 406. Pistil or carpel of the single-flowering Cherry in its normal state, o, Ovary, t, 

 Style, s, Stigma. JMg. 407. The same, cut vertically, to show the central cavity of the 

 ovary, o, with the ovule, g, suspended from its wall, 'at a point where a tundle of nourishing 

 vessels, fn, terminates, t, Style traversed by a canal, c, which runs from the stigma, s, to 

 the cavity of the ovary. 



