Page:Popular Science Monthly Volume 13.djvu/134

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THE POPULAR SCIENCE MONTHLY.

whether there is anything like a systematic direction of the labors of the ants by the queen or the major-workers, Mr. McCook replies that the queen seems to have nothing to do but to replenish the population of the community; her life is spent mostly underground. No "officers" could be seen, and each ant acts independently. The worker-majors act constantly as sentinels, and once or twice was observed what appeared to be, on their part, an effort to aid the harvesters in gathering seeds. The entrances to the interior of the formicary are circular openings or gates at the surface, connecting with tubular galleries which lead to the granaries. These granaries consist of rooms of a more or less oval shape, one above another, after the manner of floors in a house. The rooms are about half an inch in height, with hard and smooth roofs and floors. Similar rooms are employed for nurseries of the young. The rooms of each story, as also the different stories, are connected together by galleries. The author gave examples showing strong intelligence in separating white meal from arsenic, with which it had been mixed, and of the refusal of poisoned molasses.

 

Birds' Eggs and Birds' Nests.—There exists a curious relation between a bird's mode of nesting and the color of its eggs. The circumstance is noted in the Bulletin of the Nuttall Ornithological Club by Mr. J. A. Allen, who observes that nearly all birds that nest in holes, either in the ground or in trees, lay white eggs. As instances of this fact may be cited, the woodpeckers, kingfishers, bee-eaters, rollers, hornbills, barbets, puff-birds, trogons, toucans, parrots, paroquets, and swifts; while only occasionally are the eggs white in species which build open nests. A few exceptions are noted by the author to the rule, according to which only white eggs are laid in open nests; these are owls, humming-birds, and pigeons. On the other hand, in only two or three small groups of species that nidificate in holes are the eggs speckled or in any way colored. Wallace, it will be remembered, has endeavored to show that the form of nest is, as a rule, correlated to the color of the female bird: if the color is brilliant or in any way striking, the nest is concealed; and vice versa, if the female is inconspicuous in color, the nest is open. Mr. Allen, in the paper from which we are quoting, calls attention to the many weak points of Wallace's theory, and asserts that a more uniform correlation exists between color of eggs and style of nest than between the two members of Wallace's correlation. Mr. Allen, however, does not care to formulate a "law" upon the basis of the facts stated above, the exceptions being, as he says, too numerous to consist with the relation of cause and effect.

 

Subterranean Water-Courses.—It often happens, in years of great drought, that the waters of the Danube, near its source, nearly altogether disappear in the fissures and holes in the bed of the river. The proprietors of works situated farther down-stream have frequently closed these subterranean passages, to avoid losses of water. But other manufacturers, owning works on the Aach, a tributary of Lake Constance, a few miles distant from the Danube, and at an elevation some 150 metres less, contended that these holes and fissures in the bed of the Danube open into water-passages connecting with the source of the Aach; hence they applied to the courts for an injunction to prevent the stopping of these outlets. To test the truth of this theory of the Aach water-supply, 10,000 kilogrammes of common salt was thrown into the Danube at the point where it gets lost. This salt reappeared in the water of the source of the Aach. Another experiment consisted in mixing fluoresceine with the Danube-water at the same point. On October 9th, at 5 p. m., about fifty litres of this dyestuff was poured into one of the openings in the riverbed. On the morning of October 12th, the observers stationed at the source of the Aach perceived the coloration of the water, which was of an intense green. The color grew more and more intense till the evening of October 12th, and disappeared about 3 p. m. of the 13th.

 

A Bird-eating Trout.—A correspondent of Land and Water tells a well-accredited story of a trout caught in the act of swallowing a sparrow which it had seized. The trout had been kept for some time in an