COMPOUND OVARY. 275 
various extents. Thus, in the Rue (fig. 611, ov), the union 
only takes place at the base of the ovaries, the upper parts 
remaining distinct, in which case the ovary is commonly 
described as lobed. In Dianthus (fig. 602) the ovaries are 
completely united, the styles being distinct ; while in the 
Primrose (jig. 582), the ovaries, styles, and stigmas are all 
united. When two or more ovaries are thus completely united 
so as to form one body, the organ resulting from their union is 
called a compound ovary. 
Fie. 608. Fic. 609. Fic. 610. Fre. 611. 
Fig. 608. Pistil of Xanthoxylon fraxineum supported on a gynophore, g. 
The ovaries, 0, and styles are distinct, but the stigmas, s, are united. 
Fig. 609. Pistil of Horehound (Marrubium vulgare), a Labiate plant. Its 
ovaries, ov, are distinct, the styles, s, being united, and the stigmas 
distinct. Fig. 610. Pistil of Myosotis,a Boraginaceous Plant. ov, Dis- 
tinct ovaries. d. Styles united.—RFig. 611. Flower of the Rue (Ruta 
graveolens), showing the ovaries, ov, united at their bases. 
Compound Ovary.—The compound ovary formed as just 
stated may either have as many cavities separated by partitions 
as there are component ovaries ; or it may only have one cavity. 
These differences have an important influence upon the attach- 
ment of the ovules, as will be afterwards seen when speaking 
of placentation. It is necessary for us, therefore, to explain at 
once the causes which lead to these differences. Thus if we 
have three carpels placed side by side (fig. 612, a), each of 
these possesses a single cavity corresponding to its ovary, so 
that if we make a transverse section of the whole, b, we neces- 
sarily have three cavities, each of which is separated from those 
adjoining by two walls, one being formed by the side of its own 
ovary, and the other by that of the one next to it. Butif 
these three carpels, instead of being distinct, are united by 
their ovaries (jig. 613, a), so as to form a compound ovary, the 
latter must necessarily also have as many cavities as there are 
component carpels, b, and each cavity must be separated from 
those adjoining by a wall which is called a dissepiment or parti- 
tion. Each dissepiment must be also composed of the united 
se 
