222 



ESSENTIAL ORGANS. THE STIGMA. 



like bands, lamella ; so that stigmas may be bilobate, trilobate, bilamel- 

 lar, trilamellar, &c. 



458. It has already been stated, that the divisions of the stigma 

 mark the number of carpels which are united together. Thus, in Cam- 

 panula (fig. 405 bis), the quinquefid or five-cleft stigma indicates five 

 carpels, the stigmata of which are separate, although the other parts 

 are united. In Bignoniaceae (fig. 406), as well as in Scrophulariacese 

 and Acanthacese, the two-lobed or bilamellar stigma indicates a bilo- 

 cular ovary. Sometimes, however, as in the case of the styles, the 

 stigma of a single carpel may divide. It is probable that, in many in- 

 stances, what is called bifurcation of the style, is only the division of the 

 stigma. In Gramineae and Composite (figs. 301, 404), there is a bifid 

 stigma and only one cavity in the ovary. This, however, may be pro- 

 bably traced to subsequent abortion of the ovary of one of the carpels. 

 The stigma presents various forms. It may be globular, as in Mirabilis 

 Jalapa (figs. 376, 407) ; orbicular, as in Arbutus Andrachne (fig. 408); 

 umbrella-like, as in Sarracenia, where, however, the proper stigmatic 

 surface is below the points of the large expansion of the apex of the 

 style; ovoid, as in Fuchsia (fig. 399); hemispherical; polyhedral; 



405 bis 



407 408 



radiating, as in the Poppy (fig. 409), where the true stigmatic rays 

 are attached to a sort of peltate or shield-like body, which may repre- 

 sent depressed or flattened styles. The lobes of which a stigma con- 

 sists may be flat or pointed, as in Mimulus and Bignonia (fig. 406); or 

 fleshy and blunt, smooth, granular, feathery, as in many Grasses (fig. 

 410). In OrchidaceaB, the stigma is placed on the column formed by 

 the union of the styles and filaments. The situation where it occurs 

 has been called gynizus (^[ 433). In Asclepiadacese the stigmas are 



Fig. 405, bis. Stigmas, s, of Campanula rotundifolia. I, Style. 



Fig. 406. Bilamellar stigmas of Bignonia pandorea. The two lamella; are applied naturally 

 against each other in 1, while in -i they are artificially separated. 



Fig. 407. Globular stigma of Mirabilis Jalapa, t. Style. *, Stigma. 



Fig. 408. Circular stigma, s, and t, style of Arbutus Andrachne. 



Fig. 409. Pistil of Papaver somniferum, or opium Poppy, o, Ovary, s, Radiating stigmas 

 on its summit. 



Fig. 410. Pistil of Cynodon Dactylon, a Grass, o, Ovary, s, Feathery Stigmas. 



