The Twilight World of the Rain Forest
- Lincoln Barnett (1954)

Millions of years ago, before the advent of the ice ages, the earth basked in never-ending summer and its lands lay mantled almost to the poles beneath a forest cover of eternal green. Unlike the needled evergreens of temperate woods today, those antique trees bore broad leaves and bright exotic blooms. The forest they composed un-furled magnificently to north and south from its heart-land on the equator. On the equator it still stands today, reduced in area but revealing still the splendour and luxuriance it has worn for untold aeons. This is the true forest primeval-the rain forest.

Blanketing millions of square miles of moist equatorial lowlands, evergreen rain forest today covers more than a tenth of the planet's total land surface and nearly half the total forest areas of the earth. The spreading canopy of treetops, inter-woven layer on green layer, filters the sun's rays, creating below a dim and murky twilight that overcasts the forest floor and thus suppresses all but a scattered undergrowth of shrubs and sap-lings. In the dark roomy aisles between the straight, unbranching boles of the high trees the ground is relatively open, covered with only a thin carpet of leaves that flutter down in a gentle, never-ending fall the year round.

Here is an extraordinarily complex domain of life, richer in plant and animal species than any other community in nature save perhaps the sea. Where temperate zone woods may embrace a few dozen varieties of trees at most, a square mile of rain forest encompasses two or three hundred-counting only those with trunks more than a foot in diameter.

During the season of rains, wild avalanches of water recurrently descend in thunderous cloud-bursts which may disgorge thirty inches of water in as many days. At such periods the forest roof drips almost continually, even under fair skies. Beneath it, the forest corridors lie dank and swel-tering. By day the canopy of treetops, excluding wind and sun, retards evaporation; by night, like a giant greenhouse, it imprisons the heat of day. Under such conditions plant life proliferates with incredible luxuriance.

In clearings, bamboos may shoot upward at the rate of a foot a day, Plants attain enormous stature - "violets" bigger than apple-trees, "myrtles" with thigh-thick woody stems, "roses" a hundred and fifty feet high.

Largest and richest of the undisturbed primeval rain forests is the South American, which overlays a million square miles of the Amazon and Guiana river valleys from the Mato Grosso of Brazil north to the Caribbean coast. To the eyes of man this region is unforgettably majestic. Unlike woods of the temperate zones with their clearly defined layers of ground herbs, shrubs and trees, the rain forest of South America presents a bewildering façade of forests mounting on forests, like clouds on clouds.

The crowns of the trees form three or more superimposed stories: sparse and struggling young trees up to sixty feet high that strive for life in the perpetual gloom beneath the canopy; trees from sixty to a hundred and twenty feet high whose round crowns interweave to form the canopy itself; the giants, a hundred and twenty to two hundred or more feet high, whose crowns have burst through the canopy into the sunny upper air, like tropical islands above a green sea.