212 ESSENTIAL ORGANS. THE PISTIL. 



name of compound ovary ; or the union may take place by the ovaries 

 and styles, while the stigmata are disunited ; or by the stigmata and the 

 summit of the style only (fig. 380). Various intermediate states exist, 

 such as partial union of the ovaries, as in the Eue, where they coalesce 

 at their base ; and partial union of the styles, as in Malvaceae (fig. 383). 

 The union is usually most complete at the base ; but in Labiatae the 

 styles are united throughout their length, and in Apocynacea3 and 

 Asclepiadaceae, the stigmata only. 



436. When the union is incomplete, the number of the parts of 

 a compound pistil may be determined by the number of styles and 

 stigmata (fig. 383 s) ; when complete, the external venation, the 



grooves on the surface, and the 

 internal divisions of the ovary, indi- 

 cate the number. When the grooves 

 between the carpels are deep, the 

 ovary is denominated lobed, being 

 one, two, three, four, or five-lobed, 

 according to circumstances. In fig. 

 383, the nine carpels forming the 

 ovary, o, are divided by grooves; 

 and in fig. 384, a transverse section 

 c of the ovary of Fuchsia coccinea, 

 shows the four carpels which form 

 it. The changes which take place 



in the pistil by adhesion, degeneration, and abortion, are frequently so 

 great as to obscure its composition, and to lead to anomalies in the 

 alternation of parts. The pistil is more liable to changes of this kind 

 than any other part of the flower. 



437. The carpels are usually sessile leaves, but sometimes they are 

 petiolate, and then are elevated above the external whorls. This 

 elevation of the pistil may in general, however, be traced to an elon- 

 gation of the axis itself, in such a way that the carpels, in place of 

 being dispersed over it, arise only from its summit. A monstrosity 

 often occurs in the Rose (fig. 385), by which the axis is prolonged, 

 and bears the carpels,^ in the form of alternate leaves. Thus, by 

 the union of the petioles of the carpels, or by lengthening of the axis, 

 the pistil becomes stipitate (stipes, a trunk), or supported, as in the 

 Passion-flower, on a stalk (figs. 380, 382 g), called a gynophore (yvvvi, 

 pistil, and <pog!a, I bear), or thecaphore (6yx.ii, a case). Sometimes the 



Fig. 383. --Pistil of Malva Alcea. o, Nine ovaries, united so as to form one. t, Column formed 

 by nine styles united to near their summit, where they diverge and separate . Each of the divi- 

 sions of the style is terminated by a stigma, *. 



Fig. 384. Horizontal section of the four-celled (quadrilocular or tetrathecal) ovary of Fuchsia 

 coccinea. c c c c, Wall of the ovary, which is formed by four carpellary leaves, a, Quadran- 

 gular axis to which the carpels are united, o, Ovules attached to the inner margin of the 

 carpels. 



