. Introduction to structural and systematic botany, and vegetable physiology. Botany. 294 THE FLOWEK. and a single style. A pistil of two carpels may be two-celled, with two placentre, two styles, or two stigmas, &c.* * There are, however, some exceptions which qualify these statements : â 1. Each placenta being a double organ (556), it occasionally happens that, the two portions are separated more or less, as in Orobanchaceous plants, where a dicarpcUary ovary appears on this account to have four parietal placentae; either approximate in pairs (as in our Cancer-root, Conopholis), or equid
. Introduction to structural and systematic botany, and vegetable physiology. Botany. 294 THE FLOWEK. and a single style. A pistil of two carpels may be two-celled, with two placentre, two styles, or two stigmas, &c.* * There are, however, some exceptions which qualify these statements : â 1. Each placenta being a double organ (556), it occasionally happens that, the two portions are separated more or less, as in Orobanchaceous plants, where a dicarpcUary ovary appears on this account to have four parietal placentae; either approximate in pairs (as in our Cancer-root, Conopholis), or equidis- tant (as in Aphyllon). 2. Analogous to this is the case where the two constituent elements of the stigma (the only essential part of the style) separate into two half-stigmas, as is partially seen in Fig. 494, 495. The stigma, no less than the placenta, belongs to the margins of the infolded leaf (545), these margins being ovidiferouf in the ovary and stigmaiiferous in the style ; as Mr. Brown, the most profound botanist of this or any age, has clearly shown. These two constituent portions of the style or stigma occasionally separate, either entirely or in part, as in Euphorbiaceous plants, in Grasses, and especially in Drosera (Fig. 510), where there are consequently twice as many nearly distinct styles as there are parietal plaeentje in the compound ovary If the two component parts of the style of each carpel were reunited into one, in the usual manner, their number would equal the placenta, and their position would bo alter- nate with the latter. But since, in parietal placentation, each ^'^ half-placenta is confluent (not with its fellow of the same carpel, but) with the contiguous half-placenta of the adjacent carpel, it were surely no greater anomaly for the elements of such half-stigmas as those of Rrosera to follow the same course. This is precisely what takes place in Parnassia, and in other cases where the stigmas are opposite the parietal placentje; â cases whi
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