404 ON THE FEMALE EEOWER AND FRUIT OF 



these cavities exist to the same extent and with similar 

 irregularity from centre to circumference, the}^ may with 

 equal probability be considered as originating from the axis 

 or from the parietes of the ovarium. The vertical section 

 too, if viewed without reference to the external development 

 of the top of the column, exhibits a structure equally anoma- 

 lous. If, however, the corniculate processes terminating 

 the disc of the column be regarded as styles, which is surely 

 the most obvious and not an improbable view, their arrange- 

 ment would lead to the supposition that the ovarium is 

 composed of several concentric circular series of simple 

 pistilla, each having its proper placenta, bearing ovula over 

 its v.'hole surface. But the structure is so much obscured 

 by the complete confluence of the supposed component 

 parts, that this view might not at once present itself. It is 

 readily suggested, however, by the seemingly analogous 

 structure of Ilydiiora, in which the cylindrical placentae, 

 whose number is considerable and apparently indefinite, are 

 all pendulous from the top of the cavity, neither cohering 

 224] with its sides or base, wholly distinct from each other, 

 and uniformly and densely covered with ovula. 



But although this is the most obvious view suggested by 

 liydnora, a more careful examination, especially as to the 

 relation of stigmata to placentae, leads to a very different 

 notion of the composition of the ovarium in that genus : for 

 as the placentse correspond with, and may be said to be 

 continuations of the subdivisions of the stigmata, and as 

 these stigmata appear to be three in number, each with 

 numerous subdivisions diverging from the circumference 

 towards the centre of the ovarium, and each of these sub- 

 divisions bearing one or more placentae pendulous from its 

 internal surface, the ovarium of Hydnora may be regarded 

 as composed of three confluent pistilla, having placentse 

 really parietal, but only produced at the top of the cavity ; 

 the sides of which, however, exhibit no indication whatever 

 of composition. 



Between this most remarkable structure of Hydnora and 

 that of Cytimis there is some, though not perhaps a ^^ery 

 obvious analogy, each of the strictly parietal placentae in the 



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