250 



PISTILLIDIA IN CEYPTOGAMIC PLANTS. 



lariacese and Acanthacese, the two-lobed or bilamellar stigma indicates 

 a bilocular ovary. Sometimes, however, as in the case of the styles, 

 the stigma of a single carpel may divide. It is probable that in 

 many instances what is called bifurcation of the style is only the 

 division of the stigma. In Graminess and Compositse (figs. 331, 438) 

 there is a bifid stigma, and only one cavity in the ovary. This, how- 

 ever, may be probably traced to subsequent abortion in the ovary of 

 one of the carpels. The stigma presents various forms. It may be ■ 

 globular, as in Mirabilis Jalapa (figs. 410, 442) ; orbicular, as in 

 Arbutus Andrachne (fig. 443) ; umbrella-like, as in Sarracenia, where, 

 however, the proper stigmatic surface is beneath the angles of the 

 large expansion of the apex of the style ; ovoid, as in Fuchsia (fig. 

 433) ; hemispherical ; polyhedral; radiating, as 

 in the Poppy (fig. 444), where the true stig- 

 matic rays are attached to a sort of peltate 

 or shield-like body, which may represent de- 

 pressed or flattened styles ; cucullate — i.e. 

 covered by a hood, in Calabar Bean (fig. 445 a), 

 where it is situated on the apex of a declinate 

 style, bearded (hairy) on its concave surface 

 (fig. 445 6). The lobes of a stigma may be flat 

 and pointed, as in Mimulus and Bignonia (fig. 

 441 J fleshy and blunt, smooth or granular, or 

 they may be feathery, as in many Grasses (fig. 

 446). In Orchidaceae the stigma is situated 

 on the anterior surface of the column formed 

 by the union of the styles and filaments ; the 

 point where it occurs being called gynizus (p. 

 238). In Asolepiadacese the stigmas are united 

 to the face of the anthers, and along with them form a solid mass 

 (fig. 386). 



In Ceyptogamic Plants there exist organs called ■pistilUdia, 

 which have been supposed to perform the function of pistils. They 

 are hollow flask-shaped organs, like ovaries, to which the names of 

 sporangia {ff'^ro^a, a spore or seed, and ayyog, a vessel), and thecce 

 {6ri%ri, a sac), have also been given. They contain bodies called spores, 

 equivalent to ovules. These spores being capable of germination, and 

 being devoid of cotyledons, have been termed leafless phytons. The 

 sporangia, or spore-cases, are sometimes immersed in the substance of the 

 plant, as in Eiccia glauoa (fig. 447, 1) ; at other times they are sup- 

 ported on stalks, or setm (seta, a bristle), as in Mosses. In Marchantia 

 polymorpha they consist of distinct and separate expansions, having a 

 flask-shaped appearance (fig. 448), the lower enlarged part, o, contain- 



Pig. 445. Style and stigma of the Calabar Bean (Physostigma vmmosum), showing the 

 curved barbate style with hairs, a, on its concave surface, and a hooded (cucullate) stigma, b. 



Fig. 445. 



