Page:Popular Science Monthly Volume 55.djvu/151

Rh are deserving of all praise. Those little know who lightly speak on these matters how much self-denial is required in the prosecution of such researches when they are conducted, as indeed they always are, as far as I am aware, with the object of establishing new truth."

The Ruins of Xkichmook, Yucatan.—The group of ruins in Yucatan called Xkichmook was discovered by Mr. Edward H. Thompson in 1888, when he read a paper before the American Antiquarian Society embodying his first impressions of it. He has since made studies of it extending over a period of seven years. The group is about one hundred and forty miles south of Merida and forty or fifty miles east of Campeche, situated in a narrow valley between a series of rocky hills, and has to be approached by precipitous paths over the hillsides, and thence down the beds of dry arroyos whose yearly freshets wash away all vegetation. Ten buildings, including one called the Palace, and two mounds were explored, and some miscellaneous excavations were made—all of which are described in the author's paper (Field Columbian Museum), with figures of the buildings and objects. Pottery and flaked stone implements were plentiful, but polished implements and specimens of sculpture were exceedingly rare. The flat under surfaces of the ceiling stones of the vaulted chambers seem to have contained very elaborate designs; in another chamber portions of a painting were still partly preserved; in another, curious drawings or glyphs in strong black lines once existed; in another was a painted human figure, of which only the flowing headdress, a portion of the face, and certain devices issuing from the mouth and probably indicating speech, now remain. The mysterious red hand was found painted in various places, and in one a human hand in blue pigment was found, the impression of which was so fresh and perfect in places that even the minute lines of the skin were visible. In ten years of investigation among the ruins of Yucatan and Campeche not as many specimens of worked obsidian were found as could be picked up in half an hour among certain Mexican ruins; but traces of ancient fabrication of flint implements were more plentiful than anywhere else.

The Seventeen-Year and the Thirteen-Year Locusts.—The periodical cicada, or seventeen-year locust, as it is called, is distinctly American, and has the longest life period of any known insect. It is especially remarkable, Mr. C. L. Marlatt observes in his memoir upon it, in its adolescent period, the features of particular divergence from other insects being its long subterranean life of thirteen or seventeen years, and the perfect regularity with which at the end of these periods every generation, though numbering millions of individuals, attains maturity almost at the same moment. At this moment the brood issue from the ground, leaving innumerable exit holes, and swarm over trees and shrubs, filling the air with their strident calls, and laying their eggs in slits which they cut in the trees. The larvae, when hatched, fall to the ground, and quickly burrow out of sight, each "forming for itself a little subterranean chamber over some rootlet, where it remains through winter and summer, buried from sun, light, and air, and protected in a manner from cold and frost.… It lives thus alone in its moist earthen chamber," rarely changing its position unless some accident to the nourishing rootlet may necessitate its seeking another, passing the thirteen or seventeen years of its hypogeal existence in slow growth and preparation for a few weeks only of winged life in the air and light. Other cicadas appear every year, usually in comparatively small numbers. They are probably equally long in maturing, but the periods of their lives have from some cause or another been cast in "off" years. The thirteen-year broods are southern, and the shortening of their periods of development may possibly be accounted for by the longer season of warmth in the southern year giving them the number of hours or of aggregate degrees of warmth in thirteen years that the more northern broods can not receive in less than seventeen years. This, however, is only speculation, and there are difficulties in applying the supposition to make it fit all the facts; and many believe that the two