STRUCTURE OF THE FLOWER AND ITS ORGANS 2038 
separate cells’ or chambers, more scientifically known 
as locules. Fig. 154, B, shows a three-celled ovary 
seen in cross-section. The ovules are not borne indis- 
criminately by any part of the lining of the ovary. In 
one-celled pistils they frequently grow in a line running 
along one side of the ovary, as in the pea pod (Fig. 271). 
The ovule-bearing line is called a placenta ; in compound 
pistils there are commonly as many placentas as there are 
Fic. 149.—Partsofa FIG. 150.— Parts 
Fig. 147.—Tubu- Fie. 148. — Labi- Stamen. phon sos. 
lar Corolla, from ate or Ringent A, front; B, back ; a, an- ov, ovary. 
Head of Bache- Corollaof Dead ther; c, connective; sty, style. 
lor’s Button. Nettle. J; filament. stig, stigma. 
separate pistils joined to make the compound one. Pla- 
centas on the wall of the ovary, like those in Fig. 154, A, 
are called parietal placentas ; those which occur as at B, 
in the same figure, are said to be central, and those which, 
like the form represented in C’ of the same figure, consist 
of a column rising from the bottom of the ovary are 
called free central placentas. 
1 Notice that the word cell is here used in an entirely different sense from 
that in which it has been employed in the earlier chapters of this book. As 
applied to the ovary, it means a chamber or compartment. 
