30 OUTLINE OF STRUCTURAL BOTANY 
The parts of the flower are regarded as modified leaf-forms and 
the ovary is not an exception. If we suppose a leaf folded once 
with its borders united we have a conception of an ovary of a 
single carpel, from the united borders of which may arise a single 
ovule or several ovules. If two or more such folded leaves are 
combined to form an ovary we have an ovary -of several carpels 
which may be permanently separated by the infoldings of the 
elemental leaves which will form so many partitions or, should 
these infoldings not extend to the center or should, in the course 
of the process of formation, some part of the infolding borders 
fail of development the partition will be only partially or not at 
all formed and the compound carpel may show only some partial 
indications of partitions and when although the original borders 
may have united, parts of the folds are wanting there may remain 
y rae, 
LS & 
ll 
a b, 
4] 42 43 44 
Fic. 41—Carpel of Buttercup—a, shell of carpel; b, seed. 
Fic. 42—A pistil—a, ovary; b, style; c, stigma. 
Fic. 43—Diagram of attachments of ovules to placentas on the wall of the ovary. 
These placentas are known as parietal placentas. 
Fic. 44—Attachments of the ovule around a central column, The points of at- 
tachments are central placentas. 
a central column in the cavity of the ovary with only the peri- 
pheral indications of the typical structure. 
Rising from the rounded ovary is found, in a majority of the 
more typical flowers, a column which, in botany, is known as the 
style. There may be a single style which may arise from an ovary 
of a single locule or from one in which several locules are united 
or there may arise several styles from a number of carpels. The 
style differs in length and in comparative thickness in different 
flowers as in the case of the long and slender style of the tiger 
lily and in the short and thick one of the buttercup. Although, 
in its typical form it is a rounded and regular column it assumes 
other forms as in the orchid in which it is flattened and bears 
the stamen on its side or as we have seen it in the silk of the Indian 
corn where it is a long drawn out filament. Many other flowers 
may be found which afford an interesting study of this organ for 
each form of the pistil as a whole is designed so as best to promote 
the function of the organ, which is an adjunct to the process of 
