PISTIL. 87 



ed sumin't of the style, but it frequently occupies oilier situ- 

 ations, lu the Iris it is a line on the back of the triful {>eta]. 

 like style ; in some it occupies tlie side of the pistil ; in oth- 

 ers no point can be iletected, by observation, that corresponds 

 in appearance to the stiginutic surface. Tlie central part of 

 the stigma consists of a more lax tissue which leads directly 

 to the ovary, and is called the condnctiniji tissue. 



101. The sti/h\ tig. 104, h, is a vascular organ, varying in 

 length, supported by the ovary, and supporting the stigma. 

 It is generally considered an unessential organ ; but Raspail 

 says^that the style [)enetrates the ovary and becomes the pla- 

 centa, which would render its presence always necessary ; but 

 this is in oi^position to all other botanists, so t'ar as we know, 

 the placenta being considered the union of the edges of the 

 folded leaves composing the ovary. The style is some- 

 times articulated to tiie summit of the ovary, at others 

 forms a continuation of it. Alihoiiirh the style usually rises 

 from the summit of the ovary, yet in some cases it does not. 

 In the LahiatcB it comes from the base, and in others from 

 the side. These apparent variations are produced by the 

 jijjo.... >i ' vf^lopinent «»f the parts of the ovary ; one side be- 

 in. d more than the other, would, of course, turn the 

 summit to the least developed side. 



102. The Ovary, fig. 104, a, is the thickened base of 

 i.i ... • ...,j| ijj j],;jt pm.f of the organ containing the ovules, 

 aji s tiie iVuii in maturity, whatever may be its form. 

 The ovary, when the pistil is composed of a single leaf, is 

 formed by the folding of the leaf with the upper i?urfiice in- 

 wards and united by its edges, the lamina of the leaf form- 

 ing the ovary. Tiiis arrangement is well exhibited by the 

 Peach, Tlie iurrow, whicii is always seen runninjx from the 

 apex to the base of this fruit, on one side, is the united mar- 

 gins. T'!'' midrib on the opposite side is undistinguishable 

 on the sai iace, but by disseciion ihc vessels will be found lar- 

 ger on that side, and running more directly from the base to 

 the apex. i05 



103. Ti»e Placenta is the union of the two margin, of 

 the carjif'-. and bears the ovules which in maturity be- 

 come the .-eed. \\\ carefully breakinc the stone of the 

 Peach, wc shall find the kernel attached to tltat side 

 of the cavity which corresponds to the depressed liu' 

 on the surf ice, showing that tlu; kernel or nucleus deri- 

 ved its origin and support from ihat side which i.> % 

 formed by the margin of the leaf. The Cherry is an- 

 ther example of a monocarpelous pistil, Fig. 105. 



