ANGIOSPERMS 9247 
ovules are exposed on the surface of the carpel, while in 
the Angiosperms they are enclosed by the carpel as in a 
closed vessel. Gymnosperm means ‘seed naked,’ and 
Angiosperm means “‘seed in a vessel’’; hence the names of 
the groups refer to this difference in the carpels. 
The carpel of an Angiosperm flower has the general 
shape of a flask (Figs. 207 and 215, A). The bulbous 
bottom in which the ovules are enclosed is called the ovary; 
the neck of the flask, which may be short or long, is called 
the style; and upon the style, either on its top, which is 
oftén knob-like, or along its side, there is a specially pre- 
pared surface to receive the pollen, known as the stigma. 
This stigmatic surface, when ready to receive the pollen, 
is sticky; the style, unlike the neck of a flask, is usually 
solid; so that the ovary is the only part of the carpel that is 
hollow. The ovules in an ovary vary in number from a 
single one to a great 
number, and they are 
borne in a variety of 
positions on the inner 
wall of the ovary. 
In many flowers 
the carpels remain 
separate (Figs. 207 
and 215, A), as in 
the buttercups; but 
It 1s Mery COnMnOn for Fic. 215.—A, simple pistils (each one a single 
all the carpels of a earpel); B and C, compound pistils (each one 
flower to unite on Phe tas de several carpels)-—After Bere 
formation of a single 
structure, whose general outline is that of a single car- 
pel. That is, it has a single ovary and may have a single 
style (Figs. 208, C, and 215,C). It is convenient to have a 
word to apply to this ovule-containing structure, whether 
it consists of one carpel or of several organized together, 
