GYNCECIUM IN ANGIOSPERMS. 



265 



the American species of Vaccinium. In all these, the false par- 

 tition is a growth from the middle of the back of each carpel, 

 which divides its cell more or less completely into two. 



494. On the other hand, even the true dissepiments which 

 belong to such a compound ovary may be abortive or evanescent, 

 the placentae remaining in the axis combined into a column. 

 (499.) The second modification of the compound pistil (491) 

 normally has an ovary, 



495. With one Cell and Parietal Placentae. That is, the 

 placentae are borne (as the term denotes) on the wall or parietes 



of the ovary, as in the Poppy, Violet, Sundew, 

 Cistus or Helianthemum (Fig. 543), Cleome, Gen- 

 tian, and in all or most of the orders from which 

 these examples are cited. The diagram Fig. 542 

 illustrates the morphological conception of a com- 

 pound pistil of this kind. Not that it is ever sup- 

 posed to be formed by the actual combination of once 



fid 



separate leaves, any more than a gamophyllous calyx or corolla 

 is actually so produced. The conception in all such cases is that 



FIG. 539. Transverse diagrammatic section of a flower of the common Flax, show- 

 ing the ovary with false partitions extending one from the back of each cell. 540. Sec- 

 tion of a mature fruit and seeds of the same, the false partitions now complete, divid- 

 ing the five cells into ten, each one-seeded. 541. Same of a wild Flax (Linum perenne), 

 in which the false partitions remain incomplete. > 



FIG. 542. Plan of a one-celled ovary with three parietal placentae, cut across be- 

 low ; the upper part showing the top of the three leaves it is theoretically composed of, 

 approaching, but not united. 



FIG. 543. Ovary of Helianthemum Canadense, cut across, showing the ovules on 

 three parietal placentae. 



FIG. 544. Transverse section of the ovary of Hypericum trraveolens ; the three large 

 placentas meeting in the centre, but not cohering. 545. Similar section of a ripe capsule 

 of the same ; the placentae now evidently parietal 



