228 



COMPENDIUM OF GENERAL BOTANY. 



ovules are, as a rule, situated along the margins {placentcB) of the 

 carpellary leaves or leaf. The number of carpellary leaves produces 

 either a monomerous or 2^ jpolymerous gynoecium. The polymerou& 

 gynoecium may either develop into a single ovary, when it is known 

 as a syncarjpous gynoecium ; or each individual carpel may develop 

 a pistil, the polycarpous or apocarpous gynoecium {Ra^iunculaceoB). 

 Fig. 156 represents a cross-section of the polymerous syncarpous 



Fig. 156. — Cross- 

 section through 

 the ovary of 

 Paris quadrifo- 

 Ua. 



(After Krass and Lan- 

 dois.) 



Fig. 157. — Ovary of Atropa 

 Bellddonna. 



A. LoDKitudinal section ; B, cross- 

 section. (After Krass and Lan- 

 dois.) 



Fig, 158.— Central 

 placenta of Pri- 

 mula officinalis, 

 with the ovules 

 removed. 



(After Berthold and 

 Landois.) 



gynoecium of Paris quadrifolia ; it is usually known as a " four- 

 chambered ovary." Fig. 157 shows the polymerous syncarpous. 

 {two-chamlered) gynoecium of Atropa Belladonna. 



The manner in which the carjiellary leaf-margins are united 

 sometimes brings the margins nearly to the middle of the cavity of 

 the ovary. This produces what is known as axillary placentatioov 

 (Figs. 156 and 157), which is very common. More rarely the 

 margins project little or not at all into the cavity of the ovary, 

 when it is known as parietl placentation ( Violacecej. There are 

 also intermediate forms of placentation which produce the incom- 

 pletely many-chambered ovaries {Papaver). The so-called central 

 placentation (for example, of the Primulacece ; see Fig. 158) is not 

 well understood from a morphological standpoint. It seems as 

 though the floral axis (torus) produced the ovules. It is, however, 

 possible that a caulome may develop ovaries.' 



The Position and Form of Ovaries. — An ovule is said to 

 be atropous {prihotropous) or straight when it forms a direct con- 

 tinuation with its stalklet or funiculus. The ovule is said to be 

 anatropous when the funiculus extends along and is adherent to the 



1 For fear that this statement may be misleading I will state that a caulome, 

 as such, icill 7iever produce ovaries. — Trans. 



