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Page:Popular Science Monthly Volume 32.djvu/884

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THE POPULAR SCIENCE MONTHLY.

not Chinese, or nature would have been more faithfully copied; nor European, for the work would have been more carefully finished. Professor Morse, who has resided in Japan, and Mr. Tatin Basha, a Japanese, aver that it is not of that origin, Mr. Basha remarking that a skull is not considered a fit decorative object in Japan. Large masses of crystal have been found in the California locality, and small skulls made of the same material, measuring rarely more than two inches across, have often been brought from near Pachuca, in the State of Michoacan, Mexico. The skull weighs one hundred and seventy-five and one quarter ounces. The eyes are very deep hollows. The line separating the upper from the lower set of teeth has evidently been produced by a string, either held in the hand or stretched across the bow, and is very characteristic of Mexican work. The skill of these people in making such objects has been questioned, but the large masks, mirrors, and other articles of obsidian; the objects of agate, and the numerous jade and jadeite ornaments; and the fact that they made small skulls of rock-crystal and skulls inlaid with turquoise—to the fashioning of which the making of this skull was as nothing—all indicate that they might have made a large skull if a suitable stone came into their possession. Since they procured their turquoise from Los Cerilles, New Mexico, why should we doubt that they were acquainted with the California locality for rock-crystal?

 

The Nest of the "Purse-Web" Spider.—Among the natural-history papers read in the British Association was one by Dr. H. C. McCook, describing the nesting habits of the spider Atypus niger of Florida, a species which it has been found was first observed and figured, as the "purse-web spider," by John Abbott, in 1792. The nests of the Atypus are silken tubes of close texture and various lengths and sizes, which are spun against the bark of trees in nearly equal proportions above and below the surface of the ground. Some of the tubes are from twelve to fourteen inches long, and from one half inch to three quarters inch in diameter; others—the nests of the young—are a few inches long and of the thickness of a pipe-stem. The inside of the nests is white and clean; the outside is weather-stained and covered with sand. In spinning these tubes the spider first stretches a series of straight threads from a point on the bark about an inch and a half above the ground. These lines are more or less approximated, and present the appearance of a rough framework for the tube. Upon them the architect places a thickening of spinning-work, which is beaten down and spread over by the long spinners, the process resembling more that of a plasterer than of a weaver. The work is done in small sections, until the original frame is quite covered in. The lengthening of the tube is accomplished by adding to the original section until the desired length is attained. The new-made tubes were found covered on the outside with sand. The spiders were not seen in the act of sanding their nests, but a similar habit in Atypus piceus of England has been observed and described by Mr. F. Enock, who has discovered that the sand is forced through the texture of the web from the inside. The idea of mimicry has been advanced in connection with this nest-sanding. Certainly the tube does closely resemble the tree to which it is attached. But Mr. Enock's observations indicate that the spider has taken a convenient way of getting rid of the sand brought up by its mandibles from the excavations of its burrow below the surface.

 

Insects resembling Minerals.—Mr. Edward B. Poulton, discussing the resemblances which certain insect-pupæ seem to bear in color to the surface on which they; are found, thinks it probable that the gilded I pupae of Vanessidæ (butterflies) resemble glittering minerals, like mica, which is very common in many places. Their shape is very angular, and like that of minerals. Conversely, the gray pupæ resemble gray and weathered rock-surfaces; and the two conditions of rock would themselves act as a stimulus for the production of pupæ of corresponding color. The power was probably gained in some dry, hot country where mineral surfaces do not weather quickly. Once formed, it may be used for other purposes, and in certain species probably con-