292 MODIFICATIONS OF THE STIGMA.—THE THALAMUS. 
that the pistil is formed of five carpels. In the Graminacez 
(jig. 601) and Compositee (figs. 645 and 648), however, we have 
a bifid stigma, and but one cell in the ovary; but this arises 
from the non-development in the ovary of one of the two carpels 
of which the pistil in the plants of these orders is formed. 
The lobes assume different appearances : thus, they may be 
smooth, or thick and fleshy as in the Melon (fig. 647), or fea- 
thery as in many Grasses (jig. 601), or fringed or laciniate as in 
the Rumex (fig. 650, pl). 
Fic. 651. Fic. 652. Fic. 653. 
Fig. 651, s. Peltate or shield-shaped stigma surmounting the style, ¢, of a 
species of A7butus.—Fig. 652. Pistil of Daphne. o. Ovary. st. Style. 
stig. Stigma. Fig. 653. Pistil of Pansy (Viola tricolor). cal. Remains of 
calyx, ov. Ovary. sty. Style, surmounted by an irregular hooded stigma. 
When the stigmas are united, the number of parts in the 
compound stigma is usually indicated by radiating furrows, or 
grooves. When the stigmas unite and form a compound body 
upon the top of the style, which is larger than it, this compound 
stigma or head is said to be capitate; and this head may be 
either globular as in Daphne (fig. 652, stig), or hemispherical 
as in the Primrose (fig. 582), or polyhedral, or club-shaped, or 
peltate or shield-shaped as in the Arbutus (fig. 651, s), and 
Poppy (fig. 32, sti). In the Violet (fig. 653), the stigma pre- 
sents an irregular hooded appearance. 
4. THE THALAMUS. 
The extremity of the peduncle or pedicel, or any part of 
the axis upon which the parts of a solitary flower are arranged, 
has been variously distinguished by botanists as the thalamus, 
receptacle, and torus. The use of these names indifferently has 
often led to much confusion ; and the uncertainty is still further 
increased in consequence of the terms receptacle and torus 
being also sometimes applied in a different sense. Thus, that 
of receptacle is employed in a special manner, as already 
mentioned (page 198), to indicate a more or less enlarged 
peduncle bearing usually a number of flowers ; while the term 
torus is used by some botanists as synonymous with disk (page 
