264 



THE FLOWER. 



in the manner of Fig. 542-545. Between these two there is 

 every gradation. The first forms a compound ovary, 



492. With two or more Cells and Axile Placenta. For it is 

 evident that, if the contiguous parts of a whorl of two or more 

 closed carpels cohere, the resulting compound ovary should have 

 as many cells as there are carpels in its composition, and that 

 the placentae (one in the inner angle of each carpel) will all be 



brought together in the axis of the compound pistil. And the 

 partitions, termed DISSEPIMENTS, which divide the compound 

 ovary into cells, manifestly consist of the united contiguous por- 

 tions of the walls of the carpels. These necessarily are composed 

 of two layers, one belonging to each carpel ; and in fruit they 

 often split into the two layers. True dissepiments and the true 

 cells must accordingly be equal in number to the carpels of 

 which the compound pistil is composed. That is, the ovary, or 

 the resulting fruit, is Ulocular or 2-celled, trilocular or 3-celled, 

 quadrilocular or 4-celled, and so on, according to the number of 

 dissepiments or cells. 



493. There may also be false dissepiments, mostly of the same 

 character as that which in Fig. 534 divides the cell of a single 

 carpel. Such are found in Flax (Fig. 539-541) , in Amelanchier 

 or Service-berry, in Huckleberry (Gaylussacia) , and in most of 



FIG. 635. Pistil of a Saxifrage composed of two carpels or simple pistils united 

 below, but distinct above ; cut across both above and below. 



FIG. 636. Pistil of common St. Johnswort, of three united ovaries; their styles 

 distinct. 



FIG. 637. The same of another species of St. Johnswort (Hypericum prolificum), 

 the styles also united into one, which, however, may split apart in the fruit. 



FIG. 638. Pistil of Tradescantia or Spiderwort, even the three stigmas united into 

 one. The ovary in all cut across to show the internal structure. 



