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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 noth- 

 ing 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 ap- 

 peared to be, on their part, an effort to aid 

 the harvesters in gathering seeds. The en- 

 trances 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 em- 

 ployed 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 aud 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, bar- 

 bets, puff-birds, trogons, toucans, parrots, 

 paroquets, and swifts ; while only occasion- 

 ally 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 ivhite 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 at- 

 tention to the many weak points of Wal- 

 lace's theory, and asserts that a more uni- 

 form correlation exists between color of 

 eggs and style of nest than between the two 

 members of Wallace's correlation. Mr. Al- 

 len, 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, near- 

 ly altogether disappear in the fissures and 

 holes in the bed of the river. The proprie- 

 tors 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 con- 

 necting 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 com- 

 mon salt was thrown into the Danube at 

 the point where it gets lost. This salt re- 

 appeared 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 river- 

 bed. 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 swal- 

 lowing a sparrow which it had seized. The 

 trout had been kept for some time in an 



