78 VEGETABLE ORGANOGRAPHY. 



take their origin ; this is seen in several Rhamneae and 

 Celastrineae. 



It may be remarked in general, that when the torus 

 is not adherent to the calyx, or, in other terms, in hypo- 

 gynous flowers, the petals of plants of the same family 

 are either constantly free, as in the class Thalamiflorae, 

 or constantly united, as in the Corolliflorae ; whilst on 

 the contrary most families of the Calyciflorae present 

 almost indifferently the petals free or cohering, as we 

 see in the Rhamneas, Leguminosae, Cucurbitaceae, Cras- 

 sulaceas, Portulaceae, Caprifoliaceae, &c. 



We have seen what takes place when the torus ad- 

 heres to the ovary or to the calyx alone ; let us examine 

 what happens when it is adherent to both organs at once. 



It may be prolonged and united to the two organs, 

 without their being joined together ; this is observed, 

 although in a very imperfect manner — 1st, In some Le- 

 guminosae, where the torus adheres to the calyx by the 

 side where it bears the stamens, and is prolonged on the 

 other into a little sheath which surrounds the base of 

 the ovary. 2d, In the Capparidea?, where it is prolonged 

 along the base of the ovary, and where it often happens 

 that it adheres also to the base of the calyx, although by 

 a scarcely apparent prolongation. But this organization 

 is especially visible in the Passifloreee. Here the torus is 

 much developed; it expands and is united on one side to 

 the base of the calyx, which it lines with a petaloid 

 lamina, and then gives origin to one or more rows of 

 coloured filaments, free in Passiflora, and more or less 

 cohering in Murucuja. Besides this expansion, it is 

 prolonged upon the base of the ovary, which it narrowly 

 surrounds, and it is from this portion that the stamens 

 spring. Thus the Passifloreae are calyciflorous, inas- 

 much as their torus adheres to the calyx ; but they 

 differ from all the other Calyciflorag, and approach the 



