260 ORCHIDE. 
by exterior agents, such as wind, but in some instances, de- 
pendent to a certain extent on the plant itself. 
In a great number of plants with ordinary pollen, the 
slightest motion of the flower is sufficient to induce the fall 
of the pollen from the anther, and the application of part of 
it by reason of its highly divided nature, to the stigma. And 
in a great many plants, such as those with drooping flowers, 
and in which the stigma is longer than the stamens, this ap- 
plication almost necessarily must take place simultaneously 
with the dehiscence of the anthers, or in others the organs 
are so disposed, that provided the degree of development takes 
place, the application must follow. Of this Composite is a 
notable instance, and on this are partly founded the claims 
of this great family to a typically perfect development. But 
the separation of a mass, or of a few masses, from their si- 
tuation, by such sudden agency as motion of the wind etc. 
would be destructive, almost inevitably, to the chance of fe- 
cundation, because the masses are determinate, and always 
few in number, and of considerable size. Secondly because the 
stigma is placed in any thing but a prominent position, indeed 
it is in a position which affords no facility to the catching of a 
falling body. Nature has not neglected to obviate this cause, 
which would be attended with such fatal effects, and has so tied 
down the pollen-masses to the female organ, that a considera- 
ble degree of force is required to effect their separation. It 
must be borne in mind that, when this separation has been 
effected, the pollen-masses, generally remain attached to the 
substance, or part, which has been the means of effecting 
it, by virtue of the viscid nature of the gland, or its 
processes. 
This last cireumstance points prominently to some agency 
of a crawling inquisitive nature, such as that of insects. 
The fact of the gland having the same structure, and some 
of the properties of the stigmatic tissue, is worth noting, as it 
is the last to lose its situation when the masses are inclined 
to fall forward, into, or near the stigmatic depression. 
