STRUCTURE.] STYLE ITS NATURE, 365 



ovary which supports the stigma (Plate V. fig. 7./.). It is 

 frequently absent, and then the stigma is sessile : it is not 

 more essential to a pistil than the stalk to a leaf, or the claw 

 to a petal, or the filament to a stamen. Anatomically con- 

 sidered, it usually consists of a column of one or more bundles 

 of vascular tissue, surrounded by or enclosing cellular tissue; 

 the former communicating on the one hand with the stigma, 

 and on the other with the vascular tissue of the ovary. It is 

 usually taper, often filiform, sometimes very thick, and occa- 

 sionally angular : rarely thin, flat, and coloured, as in Iris 

 and in Canna. In some plants it is continuous with the 

 ovary, the one passing insensibly into the other, as in Digi- 

 talis ; in others it is articulated with the ovary, and falls off, 

 by a clean scar, immediately after fertilisation has been accom- 

 plished, as in the genus Scirpus. Its usual point of origin 

 is from the apex of the ovary ; nevertheless, cases occur in 

 which it proceeds from the side, as in Alchemilla, or even from 

 the base, as in Labiates and Borageworts. In these cases, 

 however, it is to be understood that the geometrical and 

 organic apices are different, the latter being determined bv 

 the origin of the style. For this reason, when the style 

 is said to proceed from the side or base of the ovary, it 

 would be more correct to say that the ovary is obliquely 

 inflated or dilated, or that it is gibbous at the base of the 

 style. 



There is no doubt that the style is also, in some cases, a 

 mere process of the placenta, wholly free from the carpellary 

 leaves, and not even guarded by an extension of their points. 

 This curious fact is conclusively established by Babingtonia 

 Camphorosmse, in which, as I have shown in the Botanical 

 Register, the style proceeds directly from the placenta itself, 

 and does not even touch the carpels, but is protruded through 

 a hole in the vertex of the ovary. I had previously noticed 

 an analogous fact in certain species of the genus Impatiens, 

 in the Botanical Register for 1840. 



In Impatiens macrochila it was shown that the style is 

 surrounded below its apex by five points, which are evidently 

 continuations of the backs of the carpels. These points were 

 stated to be the points of carpellary leaves, which, in such 



