XXI OUTLINES OP BOTANY. 



diadelphotts, when so united into two clusters. The term is more 

 especially applied to certain Leguminosce, in which nine stamens are united 

 in a tube slit open on the upper side, and a tenth, placed in the slit, is free. 

 In some other plants the stamens are equally distributed in the two clusters. 



triadelphous, pentadelphous, polyadelphous, when so united into three, 

 five, or many clusters. 



syngenesious, when united by their anthers in a ring round the pistil, 

 the filaments usually remaining free. 



didynamous, when (usually in a bilabiate flower) there are four sta- 

 mens in two pairs, those of one pair longer than those of the other. 



tetradynamous, when (in Crudferce) there are six, four of them longer 

 than the two others. 



exserted, when longer than the corolla, or even when longer than its 

 tube, if the limb be very spreading. 



114. An Anther (109) is 



adnate, when continuous with the filament, the anther-cells appear- 

 ing to lie their whole length along the upper part of the filament. 



innate, when firmly attached by their base to the filament. This is 

 an adnate anther when rather more distinct from the filament. 



versatile, when attached by their back to the very point of the fila- 

 ment, so as to swing loosely. 



115. Anther-cells may be parallel or diverging at a less or greater angle ; 

 or divaricate, when placed end to end so as to form one straight line. The 

 end of each anther-cell placed nearest to the other cell is generally called 

 its apex or summit, and the other end its base (36) ; but some botanists re- 

 verse the sense of these terms. 



116. Anthers have often, on their connectivum or cells, appendages 

 termed bristles (setae), spurs, crests, points, glands, etc., according to their 

 appearance. 



117. Anthers have occasionally only one cell: this may take place 

 either by the disappearance of the partition between two closely contiguous 

 cells, when these cells are said to be confluent or by the abortion or total 

 deficiency of one of the cells, when the anther is said to be dimidiate. 



118. Anthers will open or dehisce to let out the pollen, like capsules, in 

 valves, pores, or slits. Their dehiscence is introrse, when the opening faces 

 the pistil ; extrorse, when towards the circumference of the flower. 



119. Pollen (109) is not always in the form of dust. It is sometimes 

 collected in each cell into one or two little wax-like masses. Special terms 

 used in describing these masses or other modifications of the pollen will be 

 explained under the Orders where they occur. 



11 The Pistil. 



120. The carpels (91) of the Pistil, although they may occasionally 

 assume, rather more than stamens, the appearance and colour of leaves, are 

 still more different in shape and structure. They are usually sessile ; if 

 stalked, their stalk is called &podocarp. This stalk, upon which each sepa- 

 rate carpel is supported above the receptacle, must not be confounded with 

 the gynobasis (143), upon which the whole pistil is sometimes raised. 



121. Each carpel consists of three parts : 



(1) the Ovary? or enlarged base, which includes one or more cavities 

 or cells, containing one or more small bodies called ovules,. These are the 

 earliest condition of the future seeds. 



