free itself. Or a big one would bite several little ones in two, but after a while the little ones would have severed all the legs of the big one, and finally would get on his back and cut him in two. One combat was especially noticeable, and is described as follows by the author: "A big ant walked along till it met another big one, and the two shook antennæ. Just then a little one seized hold of a hind-leg of one of these big ones. Neither took any notice, but continued a rapid conversation. Suddenly other small ones came up, when the big one whose leg was grabbed turned furiously on the little one and seized him by the middle. This could not be done until the big one had doubled himself up; as soon as he had hold of his small antagonist, he lifted him in the air and snipped him in two. Meanwhile all the big one's legs had been seized by little ones, and the party seemed to turn over and over, little bits tumbling down off the wall, now a leg, now half an ant, till the big one was vanquished. The way in which the big ant turned on the little one was singularly indicative of rage. The determined manner in which he laid hold of the little one was quite human."
How the Silk-worm Moth escapes from its Cocoon.—Having heard a rustling, cutting, and tearing noise issuing from a cocoon of Actias luna, the large green swallow-tailed silk-worm moth. Prof. A. S. Packard supposed that the moth must be engaged in cutting its way out of the cocoon. And as the mode of escape is a subject of dispute among entomologists. Prof. Packard determined to observe the moth at its work. A sharp black point was seen moving to and fro, and then another, until both points had cut a rough, irregular slit, through which the shoulders of the moth could be seen vigorously moving from side to side. The slit was made in one or two minutes, and the moth worked its way at once out of the opening. Afterward, in examining two dry specimens of the same moth, this black point or spine was seen at the base of each fore-wing; Mr. Packard calls it sector coconis—the cocoon-cutter. A number of other members of the sub-family Attaci having been examined, the sector was found in them all. In the common silk-worm (Bombyx mori), the spines are not well marked, and they are quite different from those in the Attaci, and consist of three sharp points, being acute angles of the pieces at the base of the wing.
The Musk-Bison.—Ovibos moschatus (musk sheep-ox, i. e., the musk-ox), as its systematic name indicates, possesses external characters common to the sheep and the ox, and hence it has been regarded as forming the connecting link between these two species. But, as a writer in Land and Water points out, the name given to the animal by Pennant, namely, musk-bison, more correctly defines its zoölogical position. Of this interesting animal, the writer just mentioned says that it measures only about five and a half feet from the tip of the nose to the root of the tail. Its average weight is usually estimated by travelers at 700 pounds, but the author thinks that 800 pounds would probably be nearer the weight of the largest individuals. The outer hair, or fleece, is long and thick, brown or black in color, frequently decidedly grizzled, hanging far below the middle of the leg. Underneath this shaggy coat, and covering all parts of the animal, though much the heaviest upon the neck and shoulders, is found a fine soft wool of exquisite texture, of a bluish-drab or cinereous hue, capable of being used in the arts and of forming the most beautiful fabrics. It is this close under-fur which enables its wearer to withstand the bitter storms and piercing cold of arctic winters, even beyond the seventieth parallel of latitude. The head is large, ending in a rather short muzzle, though remarkably broad nose, the nostrils being bordered and separated by a naked narrow space. The forehead is convex, and both sexes are provided with horns, which are of extreme size, and not unlike those of the male of the Rocky Mountain sheep in curve and general appearance, but lacking the transverse corrugations that characterize the latter. In the male, these appendages approach so closely together in the centre of the forehead as to appear to be joined at their bases, as they undoubtedly are in old age. Leaving the point of insertion, the horns are directed outward and laterally, falling down abruptly on either side of the face, curving slightly
