THE FLOW En 



105 



134. The several distinct pistils of a 

 single flower. One cut across, 

 and one cut lengthwise, to show 

 the placentation. 



of some sort (see Fig. 138). But the name applies even 

 when no special outgrowth 

 is to be seen, 



192. Types of ovary and 

 placentation. — When the pis- 

 tils are separate and the ovaries, 

 therefore, one-celled, the typical 

 arrangement of the ovules in 

 each ovary is in a double verti- 

 cal row on the side nearest the 

 center of the flower (Fig. 134). 

 A solitary ovule may be sus- 

 pended from the top of the 

 cell, or spring from the side 

 to^^^rd the flow^er axis, or rise from the bottom. 



193. When the pistil is compounded of several carpels, various 

 arrangements of the parts are possible. The common one is that 



194. With two or more cells 

 and axile placentation (Figs. 13.5- 

 137). — Such a pistil is just what 

 would be formed if simple pis- 

 tils, like those of the Larkspur, 

 pressed together in the center 

 of the flower, were to cohere by 

 their contiguous faces. In such 

 a case the placentas are naturally 

 axile, or all brought together in 

 the axis or center. The ovary 

 has as many internal partitions, 

 or dissepiments, as there are car- 

 pels in the composition. When 

 such pistils ripen into pods 

 they often separate along these 

 lines into their elementary car- 



135 



13o-lo7. Pistils: 135, a Saxifrage, the 

 carpels or simple pistils united 

 below, free above ; 136, common 

 St. Johnswort, the styles of the 

 carpels distinct ; 137, another St. 

 Johnswort, the carpels united 

 throus^hont. 



pels. 



195. One-celled, with parietal placentae (Figs. 138, 139). — In this 

 not uncommon case it is conceived that the several original carpellary 

 cavities are thrown into one as the organ grows. The ovules now^ 

 spring from the lines of junction of the different carpels. A placenta 

 belongs here half to one carpel, half to another. At each placenta a 

 double row of ovules is apt to be found ; but the two rows originate 

 from distinct carpels. The number of carpels is still to be told from 

 the num.ber of placentae. The placentation is here termed parietal. 



