72 PISTILS. 



theory that pistils are transformed leaves, every thing relating 

 to their form, situation, and structure, may be readily explain- 

 ed. The normal number of pistils is supposed to be the same 

 as of each row of stamens, petals, &c., but pistils are more 

 liable to have their original number lessened than any other 

 organs of the flower ; yet w^hen a pistil seems solitary it will 

 often be found that there are several cohering pistils, as in the 

 lily, where three united pistils form one. The stigma is desti- 

 tute of cuticle, and is the only organ of the plant in which this 

 is wanting, except the spongioles of the root. The stigma com- 

 municates directly w^ith the tissue of the pistil, and is in the 

 living plant always moist or viscid. The ovules are attached 

 to that line which represents the cohering margins of the leaf, 

 and rest upon the seam or midrib. The pi ace7ita is a projec- 

 tion or point to which the ovules are attached. That part of 

 the carpel where the placenta is formed is the inner or ventral 

 suture^ corresponding to the margin of the folded carpellary 

 leaf, while the outer or dorsal suture corresponds to the midrib 

 of the carpellary leaf. The pistil is essential to the continued 

 existence of the plant ; it varies in mmiber in different plants, 

 some having but one pistil, and others hundreds. Linnaeus 

 founded the orders of his first twelve classes on the number of 

 these organs. When they are more than ten he did not rely 

 upon their number, which in this case is found to vary in indi- 

 \d duals of the same genus. The pistil usually consists of three 

 parts — the germ (or ovary), style^ and stigma. The ovary (Fig. 

 86, a) corresponding to the base of a pillar, the style (b) to the 

 shaft, and the stiorma ie) to the capital. 



' O \ / i _^ Fig.. 86. 



Fig. 86, g, represents the pistil of the poppy ; the 

 ovary is very large, the style is wanting, the stigma 

 sessile, or placed immediately on the ovary. The 

 style is not an essential part, but the stigma and 

 ovary are never wanting ; so that these two parts, 

 as in the poppy, often constitute a pistil. 



Ova?'!/ (or germ) is the inflated por- 

 tion of the carpel (Fig. 86, g) which con- 

 tains the ovules, or young seeds. In pass- 

 ing to maturity this organ undergoes a great change, as from 

 the ovary of a small yellow blossom is formed the pumpkin 

 and watermelon. When a pistil consists of a single carpel it is 

 simple, and the terms pistil and carpel are then synonymous ; 

 several carpels united form a compound pistil and compound 

 ovary. The ovary is said to be superior' when placed above the 

 calyx, as in the strawberry ; hiferior when below it, as in the 

 apple. The figure of the ovary is roundish in some plants, 

 cordate or angled in others. The style like the filament is 



Ovary— Ptyle. 



