Page:Popular Science Monthly Volume 18.djvu/415

Rh them. Twice she returned alone to the unequal task, reproaching bitterly, no doubt, the faithlessness of her associates.

Those who doubt our reports of the extremely timid political caution of these insect tribes will convince themselves that we are not exaggerating if they will but refer to Sir John's very interesting account of these formican Conservatives—Tories they are not, for obviously there is no blatant element in the politics of the ants. Their democracy, when they are democrats, is the democracy of the Swiss Republic, not the democracy of the Imperialists, still less the democracy of the French Revolution.—Spectator.

 

SATISFACTORY definition of life should express conditions involved in every phase of vital development, but never identified with any mode of inanimate existence. Transmutation represents one such fundamental distinction between animate and inanimate objects; for, although some inorganic combinations possess a degree of permutability consistent with substantial integrity, this in particular cases is always uniform in character and limited in extent. Ice, for example, may become successively changed into the liquid and gaseous state without chemical decomposition, but there is an intrinsic limit to such permutation, for under similar circumstances of pressure, at an unalterably fixed elevation of temperature, it invariably becomes resolved into simpler constituents.

There are apparently no such inherent restrictions to organic transmutations, which may be perpetuated indefinitely, under appropriate supplementary conditions, without perceptible intrinsic exhaustion. Yet organisms are never sufficiently independent to spontaneously evolve such progressive results, but require the constant accession of extrinsic energy to develop their included potentialities.

The sun is the physical source of extraneous energy for every species of vital change occurring on the earth's surface, as through the immediate agency of its rays vegetables are enabled to abstract from the surrounding medium those elements adapted to their special needs; and, although animals can not thus directly appropriate solar energy, yet they are enabled to utilize it by the assimilation of certain of these vegetable products which it has previously served to elaborate.

As all the progressive transmutations which indispensably constitute individual life are dependent on the constant incretion of material 