12 FLOWER-LEAVES. [chap. 



upon the top of the ovary in the pistil of the Pea, but it is 

 separated from it by a distinct stalk, abruptly narrowed 

 where it joins the ovary. This stalk supporting the stigma 

 is called the style. In many plants the stigma is without 

 a stalk, and rests upon the top of the ovary. When this 

 is the case, it is described as being sessile. In the Pea, 

 then, we have a pistil consisting of a single carpellary-leaf 

 answering to a foliage-leaf, a calyx-leaf, a corolla-leaf or 

 a staminal-leaf, but differing from each of these in having 

 the margins curled in and united about half of its length, 

 so that it becomes hollow, and suited to protect the delicate 

 seed-buds (ovules) which are borne inside upon its united 

 margins. 



Suppose, now, that instead of a single carpellary-leaf in 

 the flower, there were ten or fifteen of them arranged in a 

 close ring around the centre. The inner angle (that is, the 

 angle turned towards the centre of the flower) of each carpel 

 would correspond to the line of union of the edges of the 

 same carpel, and upon this inner angle the ovules would be 

 attached. If we suppose, further, all of these carpels to 

 cohere together into a single organ, we should have a pistil 

 similar to that of the orange-flower. The main diflerence 

 between the pistil of the Pea and that of the Orange is 

 simply this : that in the former the pistil consists of a single 

 carpel, in the latter of a number of cohering carpels. A 

 pistil consisting of a single carpel, or of two or more carpels 

 which do not cohere, is said to be apocarpous. A pistil con- 

 sisting of two or more carpels cohering, though the extent 

 of their union be ever so slight, is said to be syncarpous. 

 The pistil of the Pea is apocarpous ; that of the Orange 

 is syncarpous. In each of them we have an ovary — in 

 the former one-celled, in the latter many-celled — style, and 

 stigma. 



