FRAGMENTS OF SCIENCE. 



141 



tions are deserving of all praise. Those 

 little know who lightly speak on these 

 matters how much self-denial is re- 

 quired in the prosecution of such re- 

 searches 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, Yuca- 

 tan. The group of ruins in Yucatan 

 called Xkichmook was discovered by 

 Mr. Edward H. Thompson in 1888, 

 when he read a paper before the Ameri- 

 can Antiquarian Society embodying his 

 first impressions of it. He has since 

 made studies of it extending over a pe- 

 riod 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 Pal- 

 ace, 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 con- 

 tained very elaborate designs; in an- 

 other 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 in- 

 vestigation among the ruins of Yuca- 

 tan and Campeche not as many speci- 

 mens 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 im- 

 plements were more plentiful than any- 

 where else. 



The Seventeen - Year and the 

 Thirteen- Year Locusts. The peri- 

 odical 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 remark- 

 able, 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 subter- 

 ranean life of thirteen or seventeen years, 

 and the perfect regularity with which 

 at the end of these periods every gen- 

 eration, 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 root- 

 let, 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 acci- 

 dent to the nourishing rootlet may ne- 

 cessitate 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 aggre- 

 gate degrees of warmth in thirteen 

 years that the more northern broods 

 can not receive in less than seventeen 

 years. This, however, is only specula- 

 tion, and there are difficulties in apply- 

 ing the supposition to make it fit all the 

 facts; and many believe that the two 



