COROLLA. 
91 
tends also to render flowers more odorous ; it penetrates the del- 
icate tissue of the corollas, and expels the volatile oils. There 
are some exceptions to the laws just stated ; for some flowers are 
only odorous during the night, and some others during 
the day. Some flowers exhale fetid odours, which attract 
such insects, as are usually nourished by putrid animal sub- 
stances. Many flowers exhale sweet odours ; but however 
odours may differ, in the sensations which they produce, 
it is certain, they all have a stupifying, narcotic effect upon 
the nerves, and that it is dangerous to respire, even the 
most agreeable of them, in a concentrated state, for any great 
length of time. 
One important office of the corolla, is to secure those delicate 
and important organs which it encloses, the stamens and pistils, 
from all external injury, and to favor their developement. Af- 
ter the germ has become fertilized by the influence of the pollen, 
the corolla fades away and either falls off, or remains withered 
upon the stalk ; the juices which nourished it, then go to the germ, 
to assist in its growth, and enable it to become a perfect fruit. 
Another use of the corolla seems to be, to furnish a resting 
place for insects in search of honey. 
The corolla is supposed by Darwin to answer the same pur- 
pose to the stamens and pistils, as lungs in the animal system; 
each petal is furnished with an artery which conveys the 
vegetable blood to its extremities, exposing it to the light and air 
under a delicate moist membrane ; this vegetable blood accord- 
ing to his theory is then collected and returned in correspondent 
veins, for the sustenance of the anthers and stigmas, and for the 
purpose of secreting honey. 
Bernardin dc Saint Pierre,* author of the interesting story of 
Paul and Virginia, thinks the corolla is intended to collect the 
the rays of the sun, and to reflect them upon the stamens and 
pistils which are placed in the centre. 
After all our enquiries into the uses of the corolla, we are oblig- 
ed to acknowledge, that it seems not as important, in the econo- 
my of vegetation, as many less showy organs. 
It seems in reality designed chiefly to beautify, and enliven 
creation by its colour, and fragrance. Although we find much 
to gratify our curiosity, in inquiring into the wonders of nature, 
* This ingenious author remarks, that man seems the only animal sensi- 
ble to the sweet impressions, made by the colour and odour of plants, 
upon the senses ; but we think he has asserted too much. Do not the bruto 
creation seem to enjoy, by the sense of smelling, the freshness of the ver- 
dant fields 7 But man is very apt to say, “ see all things for my use.” 
Odours sometimes disagreeable— dangerous of respiration for a long 
time — uses of the c'orolla. 
