Page:Popular Science Monthly Volume 51.djvu/657

Rh mental law of all development; and as it certainly prevails for earthly life, so it does for the existence of human society. This principle is illustrated, and is destined to be more extensively so, from observations in the polar regions.—Translated for the Popular Science Monthly from the Deutsche Rundschau.



EOPLE in general are but little impressed by the many forms of life, be they plant or animal, with which they daily come in contact. A tree of unusual size, or a flower of exceptional form or color, attracts our attention. It is the unusual in Nature which always catches the eye. The New England boy grows to manhood under the widespreading boughs of the American elm, in sight of grass-covered mountains and winding rivers. The natural beauty of his surroundings is a part of himself. So, also, the Papago Indian sees nothing peculiar in the many forms of life characteristic of the region where he makes his home.

He can not listen to the whispering of the leaves, because the trees of his limited world do not grow them. He knows nothing of tangled woods, but draws his inspiration from the broad, hot, cactus-covered plains and the granite-walled and lava-strewn mountains.

The many and varied species of cacti, which constitute the vegetation most familiar to him, are the most peculiar of all forms of vegetable life to those who live beyond the limits of our arid region. Of all these strange plants the sahuaro, or giant cactus, on account of its great size and striking aspect, is the most impressive. We can well imagine the feeling of the early explorers when they first came in sight of these towering plants, so abundant on the foothills contiguous to Salt River Valley, and from where they extend southward far into Mexico. The finest and largest specimens that I have ever observed are growing only a few miles from Tucson, on the foothills of the Santa Catalina Mountains, where hundreds may be seen growing on a single acre, many extending their huge green columns to the height of fifty feet. The many ribs which parallel the columns are surmounted by bunches of heavy spines. With great age the spines fall away from the lower portion of the plant, leaving the broad, obtuse ribs devoid of their natural protector. This fact led the first observers to report the plant spineless.

When lighted, the spines burn readily; the flame, soon ascending, burning the spines in its path until it reaches the top. From