648 The Harmony of Creation. 
water, ammonia, carbonic acid, and some soluble salts, yet 
by its assimilative power it can produce food and medicine 
in immense variety. The beautiful tints of flowers owe 
their rainbow colours to the exquisite juices of the plant. 
The sweet odours which perfume the air, the gums, the 
balsams, and the resins, sugar, and starch, india-rubber and 
gutta-percha, medicines and foods are all distilled or fabri- 
cated by the vegetable cell. Ithe humblest lichen and the 
smallest moss, like the tiniest insect, are productions as 
wonderful as the grandest tree of the forest or the most 
gigantic animal. 
As every animal is provided, in some measure, with a 
means of defence or protection, so is the vegetable king- 
dom endowed with organs which enable it to maintain an 
existence in the midst of adverse influences, The sea- 
weed, though unable to plunge its roots into the solid rock, 
yet holds fast, so firm that the storm rarely severs it from 
its resting place. The Macrocystic pyrifera rises from depths 
of one hundred and fifty feet and then continues to float 
many fathoms on the surface of the sea. Dr. Livingstone 
mentions one plant, named Leroshua, by the native 
Bechuanas. It has linear leaves and a stalk not thicker 
than a crow quill; but on digging down a foot or eighteen 
inches, the roots enlarges to a tuber often as big as the 
head of a young child, which, on the rind being removed, 
is found to be a mass of cellular tissue filled with fluid, 
much like that of a young turnip. Botanists are aware of 
the important agency of the Ammophilia in fixing sand 
drifts and securing large tracts of fertile country, and the 
peculiar growth of the mangroves has a vast influence in 
promoting the increase of land at the expense of sea. 
Their matted roots stem the flow of waters, and retaining 
the earthy particles that sink to the bottom between them, 
gradually raise the level of the soil. On this muddy 
foundation, seeds germinate, thousands of tendrils descend 
still further till a consolidation takes place. The immense 
expansion of these littoral woods form the deltas of many 
tropical rivers. Most plants expand under the heat of the 
sun, and close in the evening or in rainy weather. The 
principal object being to preserve the pollen. In herma- 
phrodite plants, Nature provides two most efficacious 
agents, the winds and insects, which disseminate most 
perfectly the pollen, and carrying it to the stigma, fructify 
it with unerring certainty. 
Most of the plants that grow under water emerge when 
