THE PISTILS, OR GYN(ECIUM. 



105 



515. THE PARTS of a simple pistil arc three, the ovary at base, the 

 stigma at the summit, and the style, intervening. Like the filament 

 the style is not essential, and when it is wanting, the stigma is sessile 

 upon the ovary, as in crowfoot. In order to understand the relation of 

 these parts we must needs first study 



516. THE MORPHOLOGY OF THE PISTIL. As before stated, ( 380), the 

 pistil consists of a modified leaf called a carpel (icapTrbg, fruit), or carpel- 

 lary leaf. This leaf is folded together (induplicate) toward the axis, so 

 that the upper surface becomes the inner, while the lower becomes the 

 outer surface of the ovary. By this arrangement two sutures or seams 

 will be formed, the dorsal, at the back by the midvein, the ventral, in 

 front by the joined margins of the leaf. 



3TS bis 



379 bi 



885, Simple pistil of Strawberry, the stylo lateral. 3S6, Simple pistil of Crowfoot, cut to 

 show the ovule. 330, Simple pistil of the Cherry. 8S1, Vertical section showing the ovule (o), 

 style (*), stigma (). 882, Cross-section of the" same. 334, Compound pistil of Spring-beauty. 

 383, Cross-section of the same showing the 3 cells of the ovary. 378, Expanded carpcllary leaf 

 of the double cherry. 379, The same partly folded as if to form a pistil. 



517. ILLUSTRATION'. This view of tho pistil is remarkably confirmed and illus- 

 trated by the flowers of the double cherry, where the pistil may be seen in every 

 degree of transition, reverting toward the form of a leaf. This carpellary leaf 

 stands in the place of the pistil, having tho edges infolded toward each other, the 

 midvein prolonged and dilated at tho apex. 



518. If this be compared with tho pistil of tho cherry seen in tho figure (378, 

 379), no doubt can be entertained that the two sides of the leaf correspond to the 

 walls of the ovary, the margins to tho ventral suture, the midvein to the dorsal su- 

 ture, and tho lengthened apex to tho stylo and stigma. Sometimes the flower con- 

 tains two such leaves, which always present their faces toward each other. This 

 corresponds to the position of tho truo carpols, in which the ventral sutures of both 

 are contiguous. 



519. THE DOCTRIXE DEDUCED. Many other plants, as the rose, Anemone, Ranun- 

 culus, flowering almond, exhibit similar transformations of the pistil, making it prob- 

 able that it is formed upon the samo plan in all plants. Tho ovary, therefore, is the 

 blade of a leaf; folded into a sack: the style is tho lengthened apex folded into a 

 tube ; the stigma, a thickened and denuded portion of the upper margin of the 

 leaf. 



