200 



MANUAL OF BOTANY 



to placentas placed either directly on the inner wall of the ovary, 

 as in the Mignonette {fig. 424, pi) and Cactus (fig. 434) ; or upon 

 incomplete dissepiments formed, as already noticed, by the par- 

 tially infolded margins, as in the species of Orchis [fig. 425, pi) 



Fig. 436. Fig. 487. 



Fig. 435. 



Fig. 438. 



Fig. 439. 



Fkj, 435. TraDsverse section of the youug ovary of Campion {Ltjchnis), show- 

 in g five partitions proceeding from the walls of the ovary to the placentas 

 in the centre ; these partitions are destroyed by the growth of the ovary, 



so that the placentation is ultimately free-central. Fig. 436. Vertical 



section of Cerastiwm Mrsutum (CaryophyUaceai). o. Ovary, p. Free central 



placenta, g. Oviiles. s. Styles and stigmas. Fig. 437, Transverse section 



of the same with the two portions or sections separated, o. Ovary, p. Pla- 

 centa, g. Ovules, s. Styles and stigmas. Prom Jussieu. J''iff. 438. 



Vertical section of the pistil of Cyclamen {Fnmiilaceiv). s. Sepals. 



pi. Pree central placenta, st. Style, 'stig. Stigma. Fig. 439. Vertical 



section of the flower of the Plowering Rush {Buto/nus umbellalus), showing 

 the iiaier surface of the ovaries covered all over with ovules. 



and Poppy (fig. 426, plac). In parietal placentation, the number 

 of placentas corresponds to the number of carpels of which the 

 ovary is formed, and their position to the edges of the carpellary 

 leaves. "When the placentas are not attached to the inner wall 



