BOTANY. 



BOTANY. 



only one ; hence the last are called monoro/y- 

 ledons. The cotyledons, when the seed has 

 sprouted, usually rise, in the course of germi- 

 nation, out of the ground, and perform the 

 functions of leaves for a while : this is never 

 the case in wheat, or any other of the mono- 

 cotyledons ; their seeds consist chiefly of the 

 albumen or white, which is either farinaceous, 

 horny, or fleshy, and remains in the ground 

 nourishing the embryo, until its leaves and 

 roots are sufficiently perfected for that pur- 

 pose. Athjaugh the albumen is wanting in a 

 distinct form in several tribes, as those with 

 compound and cruciform flowers, &c., yet the 

 farinaceous matter lodged in the cotyledons is 

 evidently intended to supply the embryo with 

 nourishment during the first efforts of germina- 

 tion. Many plants have it distinct from the 

 cotyledons. Vitellus, the yolk, like the albu- 

 men, serves to nourish the embryo in the com- 

 mencement of germination. If the albumen, 

 as a distinct organ, is present also, the vitellus 

 is situated between it and the embryo. 



Testa, the skin, envelopes all the preceding 

 parts, and gives them their form, being itself 

 of a permanent shape, whilst they are in a 

 liquid state. It is of various textures and sub- 

 stance ; sometimes single, but usually lined 

 with a finer membrane. Hilum, or scar, marks 

 where the seed was connected with the seed- 

 vessel or receptacle. In describing the form 

 or external parts of a seed, it is always to be 

 considered as the base. 



There are several occasional appendages to 

 seeds, which may as well be considered in this 

 place. The pellich closely adheres to some 

 seeds, so as to conceal their actual skin. It 

 varies, being downy, membranous, and muci- 

 laginous, or not perceptible until moistened. 

 The tunic envelopes the seed more or less 

 loosely, being attached only at the base. The 

 feed-down is the chaffy, bristly, or feathery 

 crown, originating from the partial calyx re- 

 maining attached to the summit of a seed, 

 somewhat resembling a parachute, which we 

 see bearing along the seed of the dandelion, 

 thistle, &c. A tail is the permanent style which 

 remains as an elongated, feathery termination 

 to some seeds, as clematis. A tn'ig, a mem- 

 branous appendage, serving, as the seed-down, 

 to transport the seed it is attached to through 

 the air. It is solitary, except in some umbel- 

 liferous plants. 



We may now proceed to the last division of 

 lihe flower, which is, 7thly, the receptacle. 

 This is the common base or point of connec- 

 tion of the other parts. In compound flowers 

 i; serves as a distinguishing mark, and there- 

 lore is of importance. In the daisy it is coni- 

 eal; in the chrysanthemum, convex; carduus 

 has it hairy; chamomile, scaly; picris, naked; 

 onopordum, cellular. 



A compound flower is formed by the union 

 of several sessile florets, or lesser flowers, 

 within a common calyx; each, however, must 

 possess five stamens, their filaments divided, 



roll backwards. There are various forms, as 

 the thistle, daisy, sunflower, &c. 



When the flowers are collected round a stem 

 in a complete ring, or merely on two of its 

 sides, it is denominated a whoi-l, as in the dead 

 nettle (Lamiurn). Flowers on their own stalks, 

 standing somewhat distant from each other on 

 a common one, or axis, are denominated a ra- 

 ceme, as a bunch of currants. When they are 

 placed together on one common axis, they 

 form a spike, as in lavender (Lavandula). If 

 flowers standing on a common stalk have, in 

 proportion as they stand on it lower do\vn, 

 longer foot-stalks, so that the flowers all stand 

 nearly on a level, it is denominated a corymb, 

 as in Spircea opitlifolia, common in our gardens; 

 in the common cabbage, a corymb of flowers 

 becomes a raceme of fruit. Flowers on par- 

 tial stalks variously divided and inserted, col- 

 lected closely together and level at top, is a 

 fascicle, as in the Sweet William (Dianthus bar- 

 batus'). Sessile flowers collected together in a 

 globular figure form a head or tuft, as in Statice 

 armerio. When several flowers on stalks of 

 nearly equal length spring from a common 

 centre on a general stalk, they form an umbel, 

 as in the parsley. This is either general or 

 partial; the latter is termed an umbellule. 

 When flowers on separate foot-stalks, spring- 

 ing from a common centre, have their foot- 

 stalks variously subdivided, it is termed a 

 cyme, as in the elder (Sambucus). Flowers 

 growing on partial foot-stalks without any or- 

 der, but loosely spread on a common one, form 

 a panicle, as in the oat (Avena). When the 

 flowers of a panicle grow closely together, 

 somewhat approaching an ovate form, as a 

 bunch of grapes, the lilac, &c., it is termed a 

 thyrsus, or bunch. When the flowers are all 



upon a common axis, it 



barren and sessile 

 forms the amentum. 



The exterior covering of plants is called the 

 epidermis or cuticle, answering the same purpose 

 as the scarf-skin or cuticle of animals, viz. 

 protecting the interior and more tender parts 

 from the injuries that might arise from exces- 

 sive heat, cold, &c. ; yet, being porous, it al- 

 lows the absorption and emission of moisture 

 and air, and the admission of light It cannot 

 but have been observed how the epidermis 

 varies in different plants ; how smooth it is 

 over the petals of most flowers how downy 

 on the fruit of the peach how rough on the 

 the oak on the nettle, clothed with perforated 

 poisonous hairs. The cuticle peels off in some 

 plants, as in the cork tree. In some plants, 

 especially the Dutch rush (Equisetum hyemale), 

 it is so impregnated with silicious or flinty 

 matter as to serve as a polish for the cabinet- 

 maker, &c. 



Immediately beneath the epidermis is the 

 cellular integument; this is usuallj the seat of 

 colour, being red in the petals of the red rose, 

 blue in the common violet, &c. Leaves appear 

 to be little else than masses of cellular integu- 

 ment, enclosed in a case of epidermis, and tra- 



but their anthers united into a cylinder, j versed by numerous sap-vessels. Next to the 

 through which passes the style of a solitary j cellular integument occurs the bark. In stems 

 pistil, much longer than the stamens, and hav- j and branches but one year old this consists but 

 ng a stigma divided into two parts, which i of- one layer; in older ones there are to be 



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