THE PISTILS. 



299 



tainly is not a portion of the midrib, as has been thought) ; this is 

 evident in Tasmannia, above mentioned, where these margins are 

 actually stigmatic for almost their whole length, and in Schizandra, 

 where the stigmatic surface (known by its papillose cells or other 

 surface exposed directly to the air, without any epidermis) begins 

 externally on the ventral edge of the pistil, just above 

 the point where the ovules are attached within (Fig. 

 375). In the Pseony, in Isopyrum (Fig. 374), and a 

 great number of instances, the stigma consists of two 

 crested ridges or parallel lines running down the inner 

 face of the style ; and in a still larger number of cases 

 (as in nearly all Caryophyllacese and a part of Malva- 

 ceae )*, a continuous Astigmatic surface extends down this 

 face of the style (Fig. 384). Such unilateral stigmas 

 we accordingly take to be the normal form ; and say 

 that, while the united margins of the typical leaf composing the 

 ventral suture are turned inwards into the cell of the ovary to 

 hear the ovules, in the simple style they are exposed externally to 

 form the stigma. Where the stigma is terminal, or occupies only 



the apex of the style, we suppose 

 that these margins are infolded in 

 the style also, and form in its in- 

 terior the loose conducting tissue 

 through which a communication is 

 established between the terminal 

 stigma and the interior of the ova- 

 ry. The double nature of the 

 stigma (one lamella of which cor- 

 responds to each margin of a leaf) is still evident in the two 

 lobes which the terminal stigma exhibits in many simple pistils, 

 as in Hydrastis (Fig. 376), and Actsea (Fig. 377). 



542. The ovary contains only OVULES, or bodies destined to 

 become seeds after fertilization (420). These, in all ordinary 

 cases, are borne on the part which represents the margins of the 

 transformed leaf. They are in some sort analogous to buds, 



FIG. 374. A ventral view of a pistil of Isopyrum biternatum, showing the double stigma; 

 the ovary cut across, showing the two rows of ovules. 



FIG. 375. Vertical section of a pistil of Schizandra coccinea ; a side view. 376. Pistil of 

 Hydrastis. 377. Pistil of Actaea rubra, cut across, so as to show the interior of the ovary (the 

 ventral suture turned towards the observer). 



