OVARIUM. 41 



224. In those cases in which the pistil and ovarium 

 are formed out of one carpellary leaf, it is called simple : 

 when out of more than one, as is most frequently the 

 case, compound. 



225. When the several carpels forming a compound 

 pistil remain distinct from each other, they are termed 

 apocarpous ; when united, syncarpous. 



226. The ovarium itself is formed by the folding in- 

 wards of the carpellary leaf (fig. 39, a) ; 



and when the ovarium is composed of a 

 plurality of carpels, they are arranged 

 round a common centre, their folded 

 edges meeting, as it were, in its ima- 

 ginary axis, as at (6). 



227. Within each ovarium is con- 

 tained the ovule, or ovules (ad), which become, after im- 

 pregnation, the seeds. These ovules 



arise from a body (b), which juts out into 

 the cavity of the ovarium, called the 

 placenta, to which they are attached 

 very often by a funiculus or cord (c). 



228. Very often the placenta has its 

 origin from the folded edges of the car- 

 pellary leaf (as at 40) , and it is then 



called central ; sometimes it arises from the axis of the 

 plant itself, as in the Primroses, and p^ 41 



remains free in the cavity of the ova- 

 rium, the carpellary leaves of which 

 are not individually folded up as be- 

 fore ; it is then called free central 

 (a 41) ; and'at other times the pla- 

 centa arises from the walls orf the 

 imperfectly folded carpellary leaves {d 41), it is then 

 parietal. Central and parietal placentae with their 

 ovules are evolved by the carpellary leaf, whilst most 

 free central placentae with their ovules come directly 

 from the axis. 



2'z9. A central placenta is always alternate with its 

 own dissepiments, and opposite to those of another 

 E 3 



