Book I. EXTERNAL STRUCTURE OF PLANTS. 2U 



is that of a small globular and membranaceous bag, attached as an appendage to the roots and leaves of 

 some of the aquatics. It is confined only to a few genera, but is to be seen in great abundance on the 

 roots or leaves of the several species of utricularia inhabiting the ponds and ditches of this country ; and 

 on the leaves of aldrovanda vesiculosa, an inhabitant of the marshes of Italy. In utricularia vulgaris 

 this appendage is pear-shaped, compressed with an open border at the small end, furnished with several 

 slender fibres originating in the margin, and containing a transparent and watery fluid, and a small bubble 

 of air, by means of which it seems to acquire a buoyancy that suspends it in the water. 



1295. The reproductive organs are such parts of the plant as are essential to its propaga- 

 tion, whose object is the reproduction of the species, terminating the old individual, and 

 beginning the new. It includes the flower, with its immediate accompaniments or 

 peculiarities, the flower-stalk, receptacle, and inflorescence, together with the ovary 

 or fruit. 



1296. The flower, like the leaf, is a temporary part of the plant, issuing generally from the extremity of 

 the branches, but sometimes also from the root, stem, and even leaf, being the apparatus destined by 

 nature for the production of the fruit, and being also distinguishable, for the most part, by the brilliancy 

 of its coloring or the sweetness of its smell. 



1297. The flower. stalk is a partial trunk or stem, supporting one or more flowers, if the flowers are not 

 sessile, and issuing from the root, stem, branch, or petiole, and sometimes even from the leaf. 



1298. The receptacle is the seat of the flower, and point of union between the different parts of the flower, 

 or between the flower and the plant, whether immediate and sessile, or mediate and supported upon a 

 flower-stalk. 



1299. The inflorescence, mode of flowering, is the pecuBar mode of aggregation in which flowers are 

 arranged or distributed upon the plant. 



1330. The fruit is the rii>ened ovary, or seed-vessel which succeeds the flower. In popular language the 

 term is confined chiefly to such fruits as are esculent, as the apple, the peach, and the cherry ; but with 

 the botanist the matured ovary of every flower, with the parts contained, constitutes the fruit. 



1301. Appendages. The reproductive organs, like the conservative organs, are often 

 found to be furnished with various additional and supernumerary parts, not at all essential 

 to their constitution, because not always present, and hence denominated appendages. 

 Many of them are precisely of the same character with that of the conservative appen- 

 dages, except that they are of a finer and more delicate texture. Such are the glands, 

 down, pubescence, hairs, thorns or prickles, with one or other of which the parts of the 

 fructification are occasionally furnished. But others are altogether pecub'ar to the repro- 

 ductive organs, and are to be regarded as constituting, in the strict acceptation of the 

 term, true reproductive appendages. Some of them are found to be proper to the flower, 

 as the involucre, spathe, bracte, &c., and others to the fruit as the persisting calyx, 

 exemplified in the pomegranate. 



Sect. II. Of the External Stintcture of Imperfect Plants. 



1302. Plants apparently defective in orvQ or other of the more conspicuous parts or 

 organs, whether conservative or reproductive, are denominated imperfect. The most 

 generally adopted division of imperfect plants is that by which they are distributed into 

 iilices, equisitaceee, lycopodinse, musci, hepaticae, algJB, lichenae, and fungi. 



1303. The filiceSy equisifacets, and lycopodince, are for the most part herbaceous, and die down' to the 

 ground in the winter, but they are furnished with a perennial root, from which there annually issues a 

 frond bearing the fructification. The favorite habitations of many of them are heaths and uncultivated 

 grounds, where they are found intermixed with furze and brambles ; but the habitations of such as are 

 the most luxuriant in their growth are moist and fertile spots, in shady and retired situations, as on 

 mossy dripping rocks, or by fountains and rills of water. Some of them will thrive even on the dry ami 

 barren rock, or in the chinks and fissures of walls ; and others only in wet and marshy situations where 

 they are half immersed in water. 



13(H. The mosses {fig. 218.) are a tribe of imperfect plants of a small and diminutive size, consisting often 



merely of a root, surmounted with a tuft of minute leaves, from the centre of which the fructification 

 springs, but furnished for the most part with a stem and branches, on which the leaves are closely imbri- 

 cated, and the fructification terminal or lateral. They are perennials and herbaceous, approaching to 

 shrubby ; or annuals, though rarely so, and wholly herbaceous, the perennials being also evergreens. 



1305. TTie hepaticce are a tribe of small and herbaceous plants resembling the mosses, but chiefly consti- 

 tutijig ftronds, and producing their fruit in a capsule that .splits into longitudinal valves. In their habita- 



P 2 



