XIV INTRODUCTION TO BOTANY. 



which connects the two cells is called the connective ; it is sometimes a 

 mere line, but often variously expanded, causing the cells to separate more 

 or less. 



93. The f lament is often wanting, and the anther sessile, yet still the 

 stamen is perfect ; but if the anther, which is the essential part, be want- 

 ing, or does not contain pollen, the stamen is imperfect, and is then said 

 to be barren, abortive, or rudimentary (67), according to the degi-oe to 

 which the imperfection is carried. Imperfect stamens are often called 

 staminodia. 



94. In imsymmetrical flowers the stamens of each whorl are sometimes 

 reduced in niunber below that of the petals, even to a single one, and in 

 several Natural Orders or genera they are multiplied indefinitely. The 

 terms monandrous and polyandrous are restricted to flowers which have 

 really but one stamen, or an indefinite nimiber respectively. AYhcn 

 several stamens are united into one piece, the flower is said to be 

 synandrotis. 



95. Stamens are, 



Ttionadelphous, when united by their filaments into one company or 

 cluster. This cluster either forms a ring or tube round the 

 pistil, or, if the pistil be wanting, occupies the centre of the 

 flower. 



diadelplious, when so united into two clusters. In many Leguminosce 

 9 stamens are united by their filaments into a tube, slit on the 

 upper side, and a tenth, placed in the slit, is free. In Fumariaccce 

 there are two equal groups, each consisting of 3 (or rather |, 1, 

 ^) stamens. 



triadelphous, pentadelphous, polyadelphous^ when so united into 3, 5, 

 or several clusters. 



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

 the filaments usually remaining free ; as in the Compositce. 



didynmnous, when (as in a bilabiate flower) there are 4 stamens 

 in two pairs, those of one pair « longer than those of the 

 other. 



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

 than the others. 



96. An Anther is, 



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

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

 filament. 



versatile, when attached near their middle to the extreme point of 

 the filament, so as to swing loosely. 



innate, when firmly attached by their base to the apex of the fila- 

 ment. This is a modification of adnate. 



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

 angle ; or divaricate, when placed end to end, so as to form a nearly straight 

 line. The end of each anther-cell placed nearest to the other cell is gene- 

 rally called its apex or summit, and the other end its base ; but by some 

 authors the sense of these terais is reversed. 



98. Anthers have often on their connective, or on their cells, appen- 

 dages termed bristles (setce), spurs, crests, points, glands, etc. : according to 

 theu" appearance. (See Biosmece, Ericaceae, etc.) 



99. Anthers have occasionally only one cell ; this may take place either 

 by the disappearance of the septum between two very closely-placed 

 cells, which thus become confluent ; or by the abortion or total deficiency 

 of one cell, when the anther is said to be dimidiate, or halved. 



100. Anthers at maturity will open or dehisce, to let out the pollen, 

 either by valves, pores, or slits. The dehiscence is said to be introrse when 



