368 



CJRTICIFER^E, OR TURNIP TRIBE. 



from its possessing a number of pouches, filled with very 

 small seeds, which might be imagined to be fairy coins. The 



flowers, in this plant, are 

 arranged upon the stem in the 

 form which is termed a raceme; 

 by which it is meant, that they 

 spring from it by short stalks 

 nearly of equal length, which 

 arise at intervals ; a bunch of 

 Currants is a very good illus- 

 tration of this form. It will 

 be observed that they are 

 destitute of bracts ; the entire 

 absence of which is a peculiarity 

 of this order ; although many 

 genera of other orders are also 

 distinguished by it. The calyx 

 is formed of four little sepals ; 

 and within these are four very 

 , small white petals : the regular 



FIG. 139. SHEPHERD'S PURSE; A, whole " . . 



flower enlarged ; B, stamens and pistil ; c, arrangement of which increases 



the cross-like aspect of the 



flower. The stamens alternate with the petals, and are opposite 

 the sepals. The pistil is an oval green body, shaped something 

 like a wedge ; on the summit of which is a cushion-like stigma, 

 mounted on an extremely short style. If the ovary be cut open, 

 it will be found to contain two cells, each of which includes a 

 number of ovules hanging by slender thread-like stalks. It will 

 be observed, however, that the ovules do not originate from one 

 central placenta, but from one attached to each side-wall of the 

 ovary ; and this explains to us (as will presently appear) the 

 reason why the ovary is very often one-celled in this order, and 

 also the peculiar mode of dehiscence of the seed-vessel. The fruit 

 becomes a flat wedge-shaped body, composed of three pieces, two 

 of which, the valves^ separate from the third, which is named the 

 dissepiment ; and it is to the edges of this third piece that the 

 seeds are united. Now each valve is a carpellary leaf, the two 



