210 The Natural System of Botany. 



stance has suggested the possibility of the insects being m a( j 

 subservient to the nourishment of the plant, through an anna 

 ratus of absorbent vessels in the leaves. It is not to be sun. 

 posed, however, that such food is necessary to the existence of 

 the plant, though, like compost, it may increase its growth and 

 vigor. But however obscure and uncertain may be the final 

 purpose of such a singular organization, if it were a problem 

 to construct a plant with reference to entrapping insects, I can- 

 not conceive of a form and organization better adapted to 

 secure that end, than are found in the Dionaea muscipula,—! 

 therefore deem it no credulous inference, that its leaves are 

 constructed for that specific object, whether insects subserve 

 the purpose of nourishment to the plant or not." 



Order — Cistace^. The Rock-Rose Tribe. 



This is a small order, containing some ornamental plants, 

 cultivated in gardens under the name of Rock Rose. Several 

 of the species are very handsome, and all are very singularly 

 constructed. Their flowers are very frail, blossoming princi- 

 pally at night, and perishing under the heat of the sun. The 

 leaves of some possess a very fragrant odor. From one spe- 

 cies, the Gum Cistus, Cistus ladaniferus, a very popular garden 

 shrub, and from one or two others, is extracted the gum called 

 ladanum, the fragrance of which has caused it to be used in 

 fumigating preparations. Most of the genus Cistus belong to 

 the Southern parts of Europe and the Mediterranean islands. 

 The American genera are of little note, either for ornament or 

 use. The construction of the seed vessel, and of the embryo, 

 is very curious, and forms one of the distinguishing peculiari- 

 ties of the order. We shall offer a detailed description of it in 

 another place. 



Order — Caryophyllacbje. The Pink Tribe. 



Between the last mentioned order and this, there are two 

 or three orders which possess no general interest, and contain 

 no plants worthy of particular notice. The Pink Tribe, or 

 Chickweed Tribe, as it is often called, includes some plants 



