Magic of a forest maze: as Panama celebrates a century of nationhood, we zoom in on the intricate web of life that animates Barro Colorado, one of the country's natural treasures.

• Author: Leigh, Jr., Egbert

To many of us, the term tropical forest suggests an exotic setting, full of bizarrely shaped plants, with occasional huge, garishly colored flowers, and at least a hint of danger, as in a Henri Rousseau painting: an exuberant, often garish, and mysteriously perilous world.

A tropical forest is indeed a different world, a hot and often sticky one (although summer in Washington, D.C., can be far more disagreeably hot and sticky). Once adjusted to the heat, a visitor may be confused by an overwhelming abundance of green, and a resolute effort is often needed to bring this blur of plant profusion into focus, and resolve it into its several elements. An occasional great tree, its trunk three to six feet thick, often buttressed at the base by great flaring flanges, its first branches eighty or more feet above the ground, thrusts its crown above the confusion of a tropical canopy. Slender palms supported on stilts, leaves often lost in the canopy; little vines with leaves plastered in neat rows on rocks or tree trunks; huge woody vines thicker than a boxer's arm hanging from tree branches a hundred feet high; trees whose trunks are embraced lightly by the braided strands of a strangler fig, all contribute to this extraordinary variety Shady tracts of tall forest, easy to walk through, alternate with "light gaps" opened by the fall of a forest giant, often already choked with saplings competing to replace the fallen. Some great trees have branches festooned with ferns, orchids, bromeliads, even cacti. Getting one's leaves into the sun must be a central concern in the lives of tropical plants: they have so many ways of doing so.

Bright colors are not the norm here. One may see brightly colored fruit advertising for an animal to eat it and disperse its seeds. Normally, however, vivid colors indicate either sex, as when dazzling male birds seek mates and blazing flowers call for pollinators, or danger, as when the red, yellow, and black of a coral snake signal its power to deliver a fatal bite, or the gorgeous wings of distasteful or poisonous butterflies warn off would-be predators Leaves of a few of Barro Colorado's trees turn scarlet before falling, but the full glory of fall colors found in Vermont, Virginia, or in a forest of Japanese maples is not found in Panama.

As one approaches the island by boat (the only way to get there) in the dry season, one may see scattered trees or vines ablaze with flowers, but in the forest what one usually finds...