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Taglagallo Remarcafkus Directory 15
Page 05
Although from the moment the gills disappear the frog is a true land animal, he is obliged, on account of the fish-like character of his young, to lay his eggs in the water. For this purpose the frogs enter the pools in early spring. The surface of every country pond swarms with the bright-eyed little creatures. They have awakened from a long, cold, winter sleep, to find the spring about them and within them. Life has suddenly become abundant and joyous. Their sluggish blood flows faster, their hearts beat quicker; they leap, they swim, they swell out their throats and call to each other in various keys. The toads are with them, and the pretty tree-frogs that change their color to suit their emotions. And all are rapturously screaming. Their voices are not musical, according to man's standard, but seem to afford great satisfaction to the performers in the shrill orchestra of the swamps, who thus give vent to the flood of life that sweeps through them after the still, icy winter.
Once in a generation, a Wallace may be found physically, mentally, and morally qualified to wander unscathed through the tropical wilds of America and of Asia, to form magnificent collections as he wanders, and withal to think out sagaciously the conclusions suggested by his collections; but, to the ordinary explorer or collector, the dense forests of equatorial Asia and Africa, which constitute the favorite habitation of the Orang, the Chimpanzee, and the Gorilla, present difficulties of no ordinary magnitude; and the man who risks his life by even a short visit to the malarious shores of those regions may well be excused if he shrinks from facing the dangers of the interior; if he contents himself with stimulating the industry of the better-seasoned natives, and collecting and collating the more or less mythical reports and traditions with which they are too ready to supply him.
In animals like sea-anemones and jellyfishes the general symmetry of the body is radial; that is to say, there is no right or left, and the body might be halved along many planes. It is a kind of symmetry well suited for sedentary or for drifting life. But worms began the profitable habit of moving with one end of the body always in front, and from worms to man the great majority of animals have bilateral symmetry. They have a right and a left side, and there is only one cut that halves the body. This kind of symmetry is suited for a more strenuous life than radial animals show; it is suited for pursuing food, for avoiding enemies, for chasing mates. And _with the establishment of bilateral symmetry must be associated the establishment of head-brains_, the beginning of which is to be found in some simple worm-types.
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