130 SEXES. 



178. It is, therefore, in such plants that double flowers are to be princi- 

 pally expected. 



179. In proportion as the sexes of flowers habitually become few in 

 number, do the instances of double flowers become rare. 



ISO. Double flowers are therefore least to be expected in plants with 

 fewest stamens. 



181. Whenever the component parts of a flower adhere by their edges, 

 as in monophyllous calyxes, monopetalous corollas, and monadelphous, or 

 di-, or poly-adelphous stamens, the tendency to an unnatural multiplication 

 of parts seem checked. 



182 Therefore, in such cases, double flowers are little to be expected . 

 they are, in fact, very rare. 



183. Proliferous flowers are those in which parts that usually have all 

 their axillary buds dormant, accidentally develope such buds ; as in the Hen 

 and Chickens Daisy, in which the bractese of the involucrum form other 

 Daisy-heads in their axillae ; or, as in certain Roses, in which the carpellary 

 leaves develope leaf-buds in their axillae, so that the flower becomes a 

 branch, the lower leaves of which are coloured and transformed, and the 

 upper green, and in their ordinary state. 



184. Discoid compound flowers are those in which the central florets of 

 a flower-head acquire caroUas, like those of the circumference, as m the 

 Dahlia ; the cultivated variety of which should be called discoid, and not 

 double. 



185. These last two are so essentially different from double flowers, that 

 whatever laws may be supposed to govern the production or amelioration 

 of double flowers, can have no relation to proliferous or discoid compound 

 flowers. 



VII. Sexes. 



186. The sexes consist of two or more whorls of transformed leaves, of 

 which the outer are called S/amens (188), and the inner Plsi ilium (l^U. 



187. They are known to be modifications of leaves, because they very 

 frequently are transformed into petals which are demonstrably such [140) 

 and because they occasionally revert to the state of leaves. 



188. The stamens bear at their apex an organ, called the anther, which 

 contains a powder called pollen. 



1S9. When the anther is full grown it opens and emits the pollen, either 

 dispersing it in the air in consequence of the elasticity with which it opens; 

 or depositing it upon the stigmata (191) ; or exposing it to the action of 

 wind, or such other disturbing causes as maj*^ liberate it from its case. 



190. The pollen consists of exceedingly minute hollow balls, or cases, 

 containing myriads of moving particles, which are the fertilizing principle 

 of the stamens. 



191. The pistillum has at its base one or more cavities or cells, in which 

 bodies called ovula are placed ; and at its apex one or more secreting sur- 

 faces called sliginata. 



192. The ovula are the rudiments of seed. 



103. If the fertilizing powder of the pollen comes in contact with the 

 stigmata, the ovula in the cells of the pistillum are vivified, and become seed. 



