BOTANY. 



587 



tnents either stand distinctly separate from each other 

 or are united by a membrane at their bases, in which 

 case they are called a brotherhood (adelphia); if in 

 one united rank they are said to be one brotherhood 

 monadelphous ; if in two, three, or many ranks one 

 within another, the flower is called diadelphous, tria- 

 delpfious, or polyadelphous. If two out of four stamens 

 be shorter than the other two, the flower is said 

 to be didynamous; if two out of six are longer, the 

 flower is tetradynamous. 



In some flowers, as swallow-wore, the filaments 

 converge towards the centre, and there unite and 

 form a solid body called columna ; in which are 

 locaments for the anthers. 



The anther is composed, in most instances, of two 

 cells, containing pollen, and generally fixed to the 

 apex of the filament. If attached by their base, they 

 are said to be innate ; if by tne bark, they are adnate ; 

 and if by a single point near the middle, so as to 

 swing, they are called versatile. When fully ripe, 

 the cells burst longitudinally, or at the ends, to allow 

 the escape of the pollen. Sometimes the latter is 

 discharged by an elastic force. 



The pollen is the matter which contains the 

 fecundifying influence or principle, without the con- 

 tact of which the seeds already formed in the ovarium 

 would be abortive. The granules of the pollen are 

 of various forms ; under the microscope, they appear 

 to be globular, oval, square, &c. ; that of the sunflower 

 is like a prickly ball, of mallow toothed, like a watch- 

 wheel. Some have little tails (caudicula'], and others 

 are discharged in masses, several adhering together. 

 The dispersion of the pollen is not only caused by 

 the spontaneous action of the anthers, but is much 

 facilitated by the visits of bees and other insects. 

 The stamens are very fugitive, disappearing very 

 shortly after the pollen is discharged. 



The Disk. Between the base of the stamens and 

 that of the seed-vessel there is a vacant space, or 

 raised rim, of regular or irregular projections, called 

 by modern botanists the disk, and which, by Linnaeus 

 and his followers, is called nectarium. This member 

 of the flower is not always met with in the place 



Fig. '20. a 



assigned to it, for it is sometimes above the germen. 

 It. ul?o assumes so many different forms, that the most 

 acute botanists are puzzled to find a proper name for 

 it. Sometimes it is only a little shining cavity, or 

 slight groove, in each of the petals ; sometimes, as 



before observed, it is an erect scale at the bottom, or 

 a fringe on the throat of the petals. In some cases it 

 forms the principal member of the flower, as in the 

 narcissus and ladies' slipper, in which two instances 

 the forms do not at all accord with the title. But, 

 whatever may be the station, shape, or size of the disk, 

 it is considered in the modern schools of botany to be 

 only imperfect, or metamorphosed portions of some 

 of the other members of the flower. 



The Pistil/urn. This is the principal organ of the 

 fructification, and occupies the principal station, 

 namely, the centre. It is the female, or reproductive 

 part of the plant, and consists of three divisions, viz., 

 the seed-vessel or germen a, the style b, and the 

 stigma c. Fig. 26. 



The first and third of these divisions are constant ; 

 the second is sometimes wanting. 



The seed-vessel has all the other members of the 

 flower placed around or upon it. If below all the 

 other parts, as in the pear and gooseberry, it is said to 

 be inferior ; if above the calyx, corolla, and stamens, 

 it is said to be superior, as in the peach, orange, &c. 

 It is one or many celled, and contains one or many 

 seeds. In one class of plants it is formed of the 

 calyx, the seeds lying naked in the bottom ; hence 

 such flowers are said to be gymnosperrnous. The 

 seed-vessel is usually seated on the receptacle, here- 

 after to be described, but is sometimes elevated on a 

 peculiar kind of stem, called thecaphore^ either singly 

 or several, in a kind of bunch. 



As the ovarium is very differently constructed, and 

 assumes many different shapes, it has many charac- 

 ters applied to it. In Linnaean botany it is called 

 capsula, a little chest ; siliqua, a pod ; silicula, a short 

 pod ; legumen, also a pod ; folliculus, a little bag ; 

 drupa, a pulpy valveless integument ; pomum, an 

 apple ; bacca, a berry ; and strobilus, a woody cone. 

 Some of these names have fallen into disuse, and new 

 ones, of more apposite meaning, substituted. Dr. 

 Lindley, in his " Introduction to Botany," 1832, has 

 arranged seed-vessels into four classes, viz.: First, 

 APOCARPI, containing four divisions, namely, Utrir 

 culus, one-celled ; example, Amaranthus. Achenium, 

 one-seeded ; example, Borago. Drupa, one-celled, 

 one or two-seeded ; example, Plum. Folliculus, one- 

 celled, many seeded ; example, PaBonia. Legumen, 

 a pod ; example, Pea. Lomcntum, differs from the 

 legumen in having contractions between each seed ; 

 example, Ornithopus. Second, AGGREGATA, fruit 

 aggregate, viz., Etceris, ovaries distinct ; examples, 

 Ranunculus and Fragaria. Syncarpium, ovaries 

 cohering into a solid mass ; example, Magnolia. 

 Cynarrhodum, ovaries distinct, pericarpia hard ; ex- 

 ample, Rose. Third, Syncarpi, fruit compound, viz., 

 Caryopsis, one-celled, one-seeded ; example, Wheat. 

 Regma, three or more celled ; example, Euphorbia. 

 Carcerulus, many celled, superior ; example, Mallow. 

 Samara, a key, two or more celled, superior ; example, 

 the Ash. Pyxidtum, one-celled, many seeded ; ex- 

 ample, Anagallis. Conceptaculum, two-celled, many 

 seeded ; example, Asclepias. Siliqua, one or two- 

 celled. Silicula, similar in structure to the preceding, 

 only more rotund ; example, Shepherd s Purse. 

 Ceratium, one-celled, many seeded ; example, Cory- 

 dalis. Capsula, one or many seeded ; example, 

 Primrose. Amphisarca, many celled, many seeded, 

 pericarpium fleshy ; example, Adansonia, Tryma, 

 by abortion one-celled ; example, Juglans. Nucul- 

 two or more seeded ; example, the Grape. 



