164 ORGANOGRAPHY. BOOK 1. 



That part of the ovary from which the ovules arise is called 

 Xhe placenta ( Trophospermium, Richard ; Spermaphorum, Colum, 

 Receptacle of the Seeds.) It generally occupies the whole or a 

 portion of one angle of each cell (Plate V. fig. 1. e, 2. c, &c.), 

 and will be spoken of more particularly hereafter. It is 

 sometimes elongated in the form of a little cord, as in the 

 Hazel nut, and many Cruciferae : it is then called the umbi- 

 lical cord {funiculus umbilicalis, p)odospermium) . 



The swelling of the ovary after fertilisation is termed 



grossificatien. 



The style {tuba of old authors) is that elongation of the 

 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 consists of a column of one or more bundles of 

 vascular tissue, surrounded by 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 occasionally 

 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 Digitalis; in 

 others it is articulated with the ovary, and falls off, by a clean 

 scar, immediately after fertilisation has been accomplished, 

 as in the 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 

 Labiatae and Boragineae. In these cases, however, it is to be 

 understood that the geometrical and organic apices are differ- 

 ent, the latter being determined by 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 gibbous at the 

 base of the style. 



The surface of the style is commonly smooth ; but in Com- 

 posit«, Campanulacece, and others, it is often densely covered 

 with hairs, called collectors, which seem intended as brushes 

 to clear the pollen out of the cells of the anthers. In Lobelia 



