270 



ORGANOGRAPHY. 



Fig. 598. a. Diagram of tliree carpels 

 placed side by side but not united. 

 b. A transverse section of the ova- 

 ries of tlie same. Fip. 599. a. 



Diagram of tliree carjtels united by 

 their ovaries, the styles being free. 

 b. A transverse section of the ova- 

 ries of the same. 



Fig. 599. to it ; now, if these three car- 

 pels, instead of being distinct, 

 were united by their ovaries 

 {fig. 599, a), so as to form a 

 compound ovary, the latter 

 must necessarily also have as 

 many cavities as there are 

 component carpels (fiff. 599, 

 b), and each cavity would be 

 separated from those adjoin- 

 ing by a wall which is called a 

 dissepiment or partition. Each 

 dissepiment must be also com- 

 posed of the united sides of the 

 two adjoining ovaries, and is 

 consequently double, one half 

 being formed by one of the 

 sides of its own ovary, the other 

 by that of the adjoining ovary. 

 In the normal arrangement 

 of the parts of the ovary, it 

 must necessarily happen that 

 the styles (when they are dis- 

 tinct) must alternate with the 

 dissepiments, for as the former are prolongations of the apices 

 of the laminae of the carpellary leaves, while the latter are 

 formed by the union of their margins, the dissepiments must 

 have the same relation to the styles as the sides of the blade 

 of a leaf have to its apex : that is, they must be placed right and 

 left of them, or alternate. 



The cavities thus formed in the ovary are called cells or loculi, 

 and such an ovary would be termed three-celled or trilocular, or 

 if formed of the ovaries of two* four, five, or many carpels, it 

 would be described respectively as two-celled or bilocular, four- 

 celled or quadrilocular, five-celled or qidnquelocular, and many- 

 celled or omdtilocidar. As all dissepiments are spurious or false 

 which are not formed by the united walls of adjoining ovaries, it 

 must necessarily follow that a simple carpel can have no true 

 dissepiment, and is hence, under ordinary and normal circum- 

 stances, unilocular. 



From the preceding observations it must also follow that 

 when ovaries which are placed side by side cohere and form a 

 compound ovary, the dissepiments must be vertical, and equal 

 in number to the ovaries out of which that compound ovary 

 is formed. When a compound ovary is composed, however, of 

 several whorls of ovaries placed in succession one over the other, 

 as in the Pomegranate, horizontal true dissepiments may be 

 formed by the ovaries of one whorl uniting by their base to the 

 apices of those placed below them. 



