Page:Popular Science Monthly Volume 36.djvu/143

Rh numbers, the rabbits appeared. The twenty or twenty-five million sheep pastured on the Riverina plains are being gradually eaten out by rabbits to an extent which is represented by the decline of the flocks supported at one station from one hundred and ten thousand to twelve hundred head. The rabbits at that station have eaten up and destroyed all the grass and herbage; have barked all the edible shrubs and bushes; and have themselves perished by thousands. Foxes have been introduced for the accommodation of hunters, and in the belief that they might help to keep down the rabbits, and have become an additional and fast-increasing nuisance. Mr. C. G. N. Lockhart, in "Blackwood's Magazine," advises that the rabbits be fought by the encouragement of their natural enemies, cats and iguanas. Cats hunt them industriously, and it may be estimated that the progeny of one pair of cats will in the fifth year be equal to the slaughtering in one year of two million and a half of them. Iguanas, in the growing scarcity of opossums, their proper food, may probably learn to eat rabbits. The bounties offered for the destruction of rabbits are actually contributing to their perpetuation. The professional trappers find them a profitable game, and take care to keep up the supply. Hence they make war upon the cats with much more anxiety for their extinction than they show against the rabbits.

The Fate of the Gulf Stream.—M. J. Thoulet, applying the results of some recent observations respecting the relative levels of sea-water, describes the Gulf Stream as like a river, having a crest-line more inclined in the vicinity of its source than toward its mouth; separated by a valley of relatively abrupt inclination from the southward Newfoundland current, while its right flank has a more considerable breadth. Certain currents from the Gulf of St. Lawrence strike it so as to retard its speed and cause the deposition as a submarine delta in the slope of the "banks" which extend along the United States from the Great Bank of Newfoundland; while the eastern polar current, passing around Newfoundland on the east, strikes it perpendicularly. The waters of this current, colder but a little lighter than those of the Gulf Stream, mingle with them, and almost stop it. Its warm waters then spread out, and although they still possess a general direction toward the east, are subject to the impulsion of the winds and other accessory causes affecting the economy of currents. The Gulf Stream is then in the best condition to mollify the climate of western Europe, but no longer has individuality; it has become a simple drift without depth, and may be compared to a great river lost in swamps.

Wild Creatures of the Alps.—Martens and eagles add to the charms of the landscape for the Alpine tourist, but are hunted by the forester as his special enemies. The marten is a great destroyer of eggs and weak young creatures, and even attacks roes during the heavy snows of winter. It steals along by the animal as it labors through the heavy drifts till it becomes exhausted, when he springs upon it, bites its jugular vein, and sucks its life away. The marten does not eat its game, but drinks the blood while it is still warm, and leaves the body for other beasts and the elements. The fox hunts in a similar way, but eats the flesh till it is satisfied, and buries the rest of the carcass. The foresters do not like to pursue their predatory enemies with poison and traps, because, it is said, "they seem to think that they are taking an unfair advantage of a brother sportsman by employing such underhand means of getting rid of him." Still, they will lie in ambush to shoot their rivals. Selecting a conveniently situated building, they attract the foxes toward it by scattering carrion around at a suitable distance. Having learned the hour at which the animals are accustomed to appear, they lie in wait for them, on some moonlight night, and shoot at the shadowy forms as they come in sight. The larger birds are shot in a similar manner, but under circumstances of more labor and discomfort, because they are more wary. While the fox can be waited for in a warm room, with the window closed, the birds have to be watched from some rugged spot where it is impracticable to have a fire, and with open windows. The birds are also hunted for with a decoy horned owl—a creature toward which they are hostile; and some of the foresters keep owls for this work. While the hunters hide in some