Q28 A TEXT-BOOK OF BOTANY 
and such a word is pistil. A pistil, therefore, is any organ- 
ization of carpels that appears as a single organ with one 
ovary. <A pistil composed of one carpel is called a s¢mple 
pisttl (Figs. 207 and 215, A), and one composed of more 
than one carpel is a compound pistil (Figs. 208, C’, and 215, 
C). When a flower has one pistil, it is necessary to dis- 
cover whether it is a simple or a compound pistil, and if it 
is the latter to determine the number of carpels that enter 
into its structure. Sometimes the styles are separate 
(Fig. 215, B), or the single style is cleft more or less deeply; 
and in either case the answers to both questions are very 
apparent. But often the style is single throughout and 
does not indicate the number of carpels. In that case the 
ovary must be cross-sectioned, and if the section reveals 
more than one ovule chamber the compound character 
and the number of carpels are usually apparent (Fig. 216, 
B). Sometimes, however, a compound ovary may have 
only one ovule chamber, and in this case the number of 
A ou 
Fic. 216.—Diagrammatic cross-section of compound ovaries: A, a one-chambered 
ovule composed of three carpels; B, a three-chambered ovule.—After SCHIMPER. 
carpels may be indicated by the number of rows of ovules 
on the wall (Fig. 216, A). 
It is necessary to know something about the structure 
of the Angiosperm ovule (Fig. 217). That it is a sporangium 
containing one large spore (megaspore) that is never shed, 
was pointed out in connection with the Gymnosperms 
