30 BOTANY. 
gynizus. The individual carpels composing a pistil may be arranged like 
leaves, either in a whorl, or along a spiral. When they remain separate 
and distinct, the pistil is apocarpous ; when the carpels are all united, the 
pistil is syncarpous ; when the union of the carpels takes place by the 
ovaries alone, leaving the styles and stigmas free, the pistil is gamogastrous, 
and the ovary compound. The number of parts in a syncarpous pistil may 
be determined by the external venation, the grooves on the outside, and the 
internal divisions of the ovary. When the grooves between the carpels are 
deep, the ovary is said to be lobed. The carpels, although generally sessile, 
are sometimes petioled and elevated above the surrounding whorls. The 
union of these petioles constitutes a stipitate pistil; or when thickened and 
somewhat succulent, a gynophore, or thecaphore; when the axis is 
produced beyond the ovaries, and the styles are united-to it, we have a 
carpophore. | 
The ovules are developed on the inner side of the carpel, where the two 
edges of the carpellary leaf unite. The attachment to the edge, according 
to some authors, but doubted by others, is effected by vascular tissue, which 
traverses the carpel and sends off a branch to each ovule. At the same 
place there is a development of cellular tissue connected with the conducting 
tissue of the style and with the stigma. The union of these two tissues 
constitutes the placenta or projection to which the ovules are attached ; 
those who restrict this term to the individual branch of each ovule, style it 
the placentary, or the pistillary cord. The placenta marks the ventral or 
rinner suture of the carpel, the outer or dorsal suture corresponding to the 
midrib of the carpellary leaf. The placenta is formed on each margin or 
edge of the carpel, and hence it is essentially double, although sometimes 
appearing single; in an apocarpous pistil there are generally separate 
placentas on each margin. In the syncarpous, however, the edges of 
contiguous carpels unite to form a septum or dissepiment. When the 
dissepiments extend to the centre or axis, the ovary is divided into cavities, 
cells, or loculaments ; it may be bilocular, trilocular, quadrilocular, &c., as 
there are two, three, four, or more cells corresponding to as many carpels. 
In these cases the marginal placentas meet in the axis, and unite so as to 
form a central one. This kind of placentation is, perhaps improperly, 
termed axile. When the dissepiments do not extend to the centre, but 
merely form a projecting partition, the ovary is wnilocular, and the placentz 
parietal. Sometimes the placentz are not connected with the walls of the 
ovary, but form a column, standing free in the centre; in this case we have a 
free central placenta. In some rare cases the phenomena of placentation 
are such as to lead us to suppose that the placente are not marginal, or on 
the edges of the carpellary leaves, but rather avile, that is, prolongations of — 
the axis, the ovules being lateral buds, and the carpels verticillate leaves 
united together around the axis. 
Divisions in ovaries, not formed by the edges of contiguous carpels, are 
called spurious dissepiments. These, when horizontal, are termed phrag- 
mata. The prolongation of the edges of the placentz in a replum sometimes 
subdivides the ovary. 
30 
