STRUCT!' KK OF TIIK FLO \VKIl AND ITS ORGANS 203 



separate cells 1 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 



stiff c& 



sty 



FIG. 147. Tubu- 

 lar Corolla, from 

 Head of Bache- 

 lor's Button. 



FIG. 149. Parts of a 

 FIG. 148. Labi- Stamen, 



ate or Ringent A, front ; B, back ; a, an- 

 Corolla of Dead ther ; c, connective; 

 Nettle. /, filament. 



FIG. 150. Parts 

 of the Pistil. 



ov, ovary. 



sty, style. 

 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 O 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. 



