1280. Every leaf that has been closed in a vesicular or tubular form is a _follicle_ or _carpel_. There are therefore uni-, bi-, and tri-locular ovaria, &c. The loculi or cells of the ovarium are none other than closed carpels. As many therefore as there are of the former, so many are there of the latter, and vice versâ. The septa or partition-walls are none other than the involuted edges of the closed and confluent carpels. 1281. Uni-locular ovaria consist therefore only of one leaf. The legume is only a compressed carpel. 1282. Every carpel or every cell has its raphé or suture directed inwards or along the axis of the flower. For the leaves are always so conjoined that the two halves of the upper or inner side stand counter to each other. 1283. All other sutures are adventitious and, by their mode of dehiscence, determine those parts of the ovarium which are called valves. These sutures are either _dorsal_ or on the back of the carpel, e. g. _capsula loculicida_; _conjunctive_, where two carpels abut against each other, e. g. _capsula septicida_; or finally, between both by the side of the dorsal suture, so that the valve springing up resembles a shutter, as in many siliquæ or pods. 1284. The columella of the ovary is none other than the internal edge of the carpels from which the leaf-wall has been freed. 1285. Each carpel-leaf is to be regarded as the common petiole of a pinnate leaf, upon whose lateral petioles the seeds depend. The seeds always hang therefore upon the inner angle of the cells. 1286. As the parts of the corolla alternate with the calyx, so do the carpels or cells of the ovary with the corolla; they stand therefore opposite the parts of the calyx or are situated in front of them. 1287. The parts of the ovary follow also the uneven series of numbers, one, three, five. The number two is usually found in irregular, e. g. the labiate, corollæ. 1288. If few cells be present as parts of the flower, the carpels are then to be regarded as arrested. In the personate corollæ three are arrested, but in the papilionaceous, four. The legumen is only a fifth part of the ovarium. 1289. The development of the carpels stands usually in an inverse relation to the size of the parts of the corolla. Thus the legume is situated between the two insignificant petals of the keel, opposite to the large vexillum; in the Personatæ a carpel is situated in the fissure of the upper lip; upon the lower lip, consisting of three lobes, only one carpel is situated, which consequently supplies the place of four, and is therefore also larger. 1290. The stages of leaf-formation are also displayed in the matured state of the ovarium. The _radical_ or _scale-leaf_ is repeated in the _cariopsis_; as in the grasses, orachs, nettles, and such like plants.