XXV111 INTRODUCTION. 



113. Stamens are 



monadelphous, when united by their filaments into one cluster. This 

 cluster either forms a tube round the pistil, or, if the pistil is wanting, occupies 

 the centre of the flower. 



diadelphous, when so united into two clusters. The term is more espe- 

 cially 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 are four sta- 

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



tetradynamous, when (in Crucifera) 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 appearing 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 ad- 

 nate anther when rather more distinct from the filament. 



versatile, when attached by their back to the very point of the filament, so 

 as to swing loosely. 



115. Anther-cells may he 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 reverse 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 it is towards the circumference of the flower. 



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

 lected 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 a podocarp. This stalk, upon which each separate carpel is sup- 

 ported 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. 



