49^ 



PHANEROGAMS. 



A poly car pellary ovary is always the result of the union of all the carpels of a 

 flower, the number being usually two, three, four, or five, arranged in one whorl, and 

 the floral axis terminating in the midst of them. If the separate carpels remain open, 

 and cohere in such a manner that the right margin of one unites with the left 

 margin of another, the result is a unilocular polycarpellary ovary. The placentation 



FIG. ■i'^^.—Phaseohis vulgaris; A horizontal section through the flower-bud, / calyx-tube, c corolla, y^ filaments of the outer, 

 a anthers of the inner starainal whorl, K carpel ; B longitudinal section of the carpel, with the ovules SK and stigma n ; C, D, E 

 horizontal sections of carpels of different ages, SK the parietal ovules, g- mid-rib of the carpel. 



is in this case parietal when the coherent margins project only slightly inwards, as 

 in Reseda, Viola, &c. But if the coherent margins of the carpels project further 

 inwards, the cavity of the ovary becomes imperfectly multilocular, the chambers 

 being connected with one another in the centre, as in Papaver, where the imperfect 

 dissepiments are covered on both sides by a number of ovules. A bi- or multilocular 



Fig. 3SS.— Gynxceum of Saxifyaga cordi/olia ; A longitudinal section, g style, n stigma ; B horizontal section " 



at different heights, / placenta. 



polycarpellary ovary results when the margins of the carpels project inwardly so 

 far that they meet or cohere either in the axis or periphery of the ovary, the 

 elongation of the floral axis in the centre frequently contributing to this result. 

 The mode of cohesion of the carpels in multilocular ovaries may vary greatly in 

 other respects, according as it takes place along the whole length of their inflexed 

 margins, or only below, while the upper parts resemble a whorl of monocarpellary 



