568 
PHANEROGAMS. 
ovary (as in Fragaria and Alchemil/a). If this occurs with each of the carpels of a 
polycarpellary ovary, the ovary itself appears to be depressed in the middle, and the 
style rises from the depression (Figs. 387, 388). In Labiatae and Boraginese this 
peculiarity is especially conspicuous, the four lobes of the bilocular ovary forming 
strong protuberances (Fig. 390, A, B), so that the style finally appears to spring 
from between four parts of the ovary which seem to have scarcely any connection 
with one another, and is hence termed a gynohasic style. 
The style may be hollow, that is, it may be penetrated by a channel consisting 
of a narrow elongation of the cavity of the ovary, as in Butomus (Fig. 382, B, F)^ 
where it opens on the hairy surface of the stigma; or in Viola (Fig. 395), where 
the channel is broad, and opens above into the spherical cavity of the stigma ; 
or in Agave and Fourcroya, where the style is hollow throughout its whole length 
and open to the stigma, the simple channel dividing 
below into three tubes which run into the loculi of 
the ovary, a phenomenon which occurs also in other 
Liliaceae \ In other cases it is at first hollow, as in 
Anagallis (Fig. 392, B\ but becomes afterwards filled 
up by the growth of the tissue. There is usually no 
channel to be detected in the style when the pistil is 
ready for fertilisation, or at least not in its upper part; 
in the place of this its centre is occupied by a mass 
of loose tissue, the ' conducting tissue,' through which 
the pollen-tubes grow till they reach the cavity of the 
ovary. The external form of the style is usually 
cylindrical, filiform, or columnar, sometimes prismatic 
or ribbon-shaped ; in the Iridese it generally attains 
a considerable size; in Crocus it is very long, tripartite 
above, each division being deeply hollowed out like 
a cup ; while the genus Iris is distinguished by its 
three free broad petaloid coloured styles. Sometimes 
the portion of the style which belongs to each carpel 
branches, as in Euphorbiaceae, where a tripartite style, 
each arm of which bifurcates, corresponds to the three 
carpels. The style frequently remains very short, and then has the appearance, of 
being a mere constriction between the ovary and stigma, as in Vitis. 
The Stigma ^ in the narrower sense of the term, is the part of the style which 
is destined for the reception of the pollen. When pollination takes place it is 
covered with a viscid secretion, and usually with delicate hairs or short papillae, 
constituting a glandular structure which is sometimes merely a peculiarly developed 
portion of the surface of the style, sometimes a special organ of very variable ap- 
pearance attached to it. The form of the stigma always has an intimate connection 
with the mode of conveyance of the pollen by insects or otherwise, and can be 
understood and explained only when these facts are taken into consideration. A few 
Fig. 395. — Long-itudinal section through 
the sjynreceum of Viola tricolor; SK the 
anatropous ovules, gh channel of the style, 
o its opening: in the liollow of the stigma 
which is filled with the stigniatic secretion 
are pollen-grains which are putting out their 
pollen-tubes. 
^ Zuccarini, Nova Acta Ac. Leopold, XVI. pt. II. p. 665. 
^ [Bcliiens, Untersuch, ueb. d. anat. Bau des Griffels und der Narben, Göttingen 1875.] 
