FECUNDATION. — 121 
CHAP. IL—FECUNDATION. 
464, Tuts operation consists in the action of the pollen 
on the ovule, which is thereby impregnated, that is, excited 
to a new and vigorous mode of action, by which it increases 
in size, all its parts are fully developed, and at last it becomes 
a seed, capable, when placed in a situation favourable to its 
_ growth or germination, of producing a full grown plant si- 
milar to that which gave it birth. 
465. To effect this, it is necessary that the pollen con- 
tained in the anther of the stamen be allowed to escape, 
which takes place by the dehiscence of the anther; and that 
this pollen be brought into contact with the stigma, the 
moist surface of which causes the bags or vesicles to burst, 
and emit the tube with the vivifying mucous fluid, which is 
then conveyed along the style to the foramen (452), which _ 
admits it to the nucleus or kernel (452), there to produce Hs 
peculiar effects. 
466. The pollen is conveyed to the stigma in various 
ways. In many hermaphrodite plants (288) the stamens are 
longer than the pistil; and the pollen, when it escapes from 
the anther, naturally falls on the stigma. In such cases, as 
Linneus remarked, the flower is generally erect. When 
_ the stamens are shorter than the pistil, the flower frequently 
hangs downwards or droops, thus still enabling the pollento 
fall on the stigma when it escapes. When the stamens are _ 
short, and the flower erect, there is frequently a nectary ae 
at the bottom of it, which attracts insects in search of 
honey; these become. covered with pollen, which | falls” 
from them on the stigma as they fly out. The stamens of 
ty, by which they are enabled to bend towards the 
and — their pollen, at afterwards to their ws 
