378 FOURTH GROUP. SEED-PLANTS. 



which we shall meet with presently in the inferior ovary of the Compositae. It does 

 not often happen that the axis rises free inside the wide cavity of the ovary and 

 produces ovules laterally, as in Primulaceae (Fig. 309) and Amarantaceae (Celosia 

 according to Payer). 



The inferior ovary of epigynous flowers is due to the retardation or entire 

 cessation of the growth of the young floral axis at its apex, while the tissue of the 

 circumference rises up as an annular wall and produces the perianth-leaves, the 

 stamens and carpels on its free margin (Fig. 310, 311); the hollow structure thus 

 formed is at first open above, but is afterwards roofed over by the carpels which 

 close together above it ; the apical point of the axis lies at the bottom of the cavity 

 which is cup-shaped or elongated into a tube. Notwithstanding this remarkable 

 displacement of the axial parts, the structure of the inferior ovary resembles in almost 

 all respects that of the free polymerous ovary; it can like the latter be unilocular 

 or plurilocular, and if it is unilocular, the placentation may be basilar or parietal. 

 If the placentation is basilar, the ovule sometimes appears as the terminal structure 

 of the axis, as for example the erect ovule of the Juglandeae ; in the Compositae 

 on the other hand the single anatropous ovule is not terminal but lateral, the floral 

 axis being often distinctly visible as a small prominence beside the funiculus, and 

 in abnormal cases continuing to grow on as a leafy shoot. In Samolus the apex 

 of the floral axis rises inside the unilocular inferior ovary as it does inside the 

 superior ovary of the rest of the Primulaceae, and forms numerous lateral ovules. 

 If the placentas of the unilocular inferior ovary are parietal, they form two, three, 

 four, five or more elevations running longitudinally from above downwards or from 

 below upwards, and bear two or more rows of ovules, as in the Orchideae and 

 Opuntia\ these placentas, which project more or less into the cavity of the ovary, 

 may be regarded as prolongations of the margins of the carpels running down the 

 inner surface of the wall of the ovary. The same may be said of the longitudinal 

 dissepiments of the plurilocular inferior ovary, which may have the same varieties 

 of structure as have been already described in the case of the superior ovary of 

 the same kind ; the dissepiments may either meet in the middle and develope their 

 placentas in the inner angles of the loculi (Fig. 268), or may split into two lamellae 

 which are then recurved and produce the ovules in the middle of the loculus, as 

 in the Cucurbitaceae. Usually two, three or more carpels take part in the formation 

 of the upper portion of the inferior ovary, and the prolongations of their margins, 

 as was said above, run downwards and form the parietal placentas of the unilocular 

 or the dissepiments of the plurilocular ovary; in such cases the inferior ovary like 

 the similarly constructed superior ovary must be termed polymerous, since the 

 name refers to the number of the carpels. Examples of a monomerous inferior 

 ovary appear to be very rare; Hippuris vulgar is (Fig. 272) is one, with a single 

 carpel containing one pendulous anatropous ovule. 



The style is formed by the prolongation of the carpel above the ovary ; in the 

 monomerous ovary there is therefore only one style (Figs. 299, 301), but this may 

 be branched; if the ovary is polymerous, the style consists of as many parts as 

 there are carpels; these parts may be free from immediately above the ovary 

 (Fig. 303), or they cohere for a certain distance above it and then separate higher 

 up, or lastly they cohere along their whole length (Fig. 305 G, Fig. 307). Though 



