I go on with Figuier:  the next passage is very valuable.

5.  “The tige is the part of plants which, directed into the air, supports, and gives growing power to, the branches, the twigs, the leaves, and the flowers.  The form, strength, and direction of the tige depend on the part that each plant has to play among the vast vegetable population of our globe.  Plants which need for their life a pure and often-renewed air, are borne by a straight tige, robust and tall.  When they have need only of a moist air, more condensed, and more rarely renewed, when they have to creep on the ground or glide in thickets, the tiges are long, flexible, and dragging.  If they are to float in the air, sustaining themselves on more robust vegetables, they are provided with flexible, slender, and supple tiges.”

6.  Yes; but in that last sentence he loses hold of his main idea, and to me the important one,—­namely, the connexion of the form of stem with the quality of the air it requires.  And that idea itself is at present vague, though most valuable, to me.  A strawberry creeps, with a flexible stem, but requires certainly no less pure air than a wood-fungus, which stands up straight.  And in our own hedges and woods, are the wild rose and honeysuckle signs of unwholesome air?

  “And honeysuckle loved to crawl
  Up the lone crags and ruined wall. 
  I deemed such nooks the sweetest shade
  The sun in all his round surveyed.”

It seems to me, in the nooks most haunted by honeysuckle in my own wood, that the reason for its twining is a very feminine one,—­that it likes to twine; and that all these whys and wherefores resolve themselves at last into—­what a modern philosopher, of course, cannot understand—­caprice.[36]

7.  Farther on, Figuier, quoting St. Hilaire, tells us, of the creepers in primitive forests,—­“Some of them resemble waving ribands, others coil themselves and describe vast spirals; they droop in festoons, they wind hither and thither among the trees, they fling themselves from one to another, and form masses of leaves and flowers in which the observer is often at a loss to discover on which plant each several blossom grows.”

For all this, the real reasons will be known only when human beings become reasonable.  For, except a curious naturalist or wistful missionary, no Christian has trodden the labyrinths of delight and decay among these garlands, but men who had no other thought than how to cheat their savage people out of their gold, and give them gin and smallpox in exchange.  But, so soon as true servants of Heaven shall enter these Edens, and the Spirit of God enter with them, another spirit will also be breathed into the physical air; and the stinging insect, and venomous snake, and poisonous tree, pass away before the power of the regenerate human soul.

8.  At length, on the structure of the tige, Figuier begins his real work, thus:—–­