Throughout the entire realm of nature, in the animal world as well as in the vegetable, the development of life increases in energy, and in the variety and perfection of the types, with the increasing intensity of light and heat, from the poles to the equator.
TROPICAL LIFE
Within the tropics, under the stimulating rays of a vertical Sun, grow the most dense and varied forests, the most expanded foliage, and the largest and the most brilliant flowers. Here, also, are found the most delicious fruits, the most powerful aromatics, the greatest variety of plants capable of affording sustenance to man, and the largest number of those which contribute to the luxuries of civilized life.
In the tropical regions, also, are found the greatest variety of land animals; with the highest types, the greatest stature, the most intense activity, and the keenest intelligence exhibited in the brute creation.
WHERE THE MOST POWERFUL
ANIMALS ARE FOUND
This zone is the home of the gigantic elephant and giraffe; of the lion and the tiger, the most powerful of all the beasts of prey; and of the gorilla, chimpanzee, and ourang-outang, of all animals most resembling men.
Here, also, are the ostrich, the largest and most powerful of birds; the condor, surpassing in size all other birds of flight; and the humming-birds of South America, the smallest of the feathered tribes, unsurpassed in brilliancy of coloring, rapidity of motion, and grace of form.
In the same zone are those enormous reptiles, the crocodile and the boa-constrictor, with the hooded snakes and other serpents of most deadly venom; and insects of all sizes in indescribable profusion.
LIFE IN THE TEMPERATE ZONES
In the Warm-Temperate Zone, though the Sun never reaches the zenith, yet during the long summer his rays are almost vertical; while the winter is so mild that snow and ice are of rare occurrence.