that "the substance when analyzed consisted of sulphuric acid and lime, and, when dissolved in water and the solution allowed to evaporate, it crystallized in the well-known form of gypsum; the crystals being all alike, there being no amorphous matter among them." Mr. Murray's conclusion is that in "placing Bathybius among living things the describers of it committed an error."
Eccentricity in Wood-Growth.—Mr. T. S. Gold writes as follows, in the Gardener's Monthly, concerning the unequal deposition of wood in growing trees but partially exposed to the action of the wind: "A chokecherry sprang from seed in front of my piazza, close to it, and could only be moved by the winds laterally. The section of the trunk was elliptical, the longer diameter being nearly double the shorter. Since the tree has grown above the roof of the piazza the trunk is becoming less elliptical. A young plum-tree standing close by the side of an out-building was killed by mice, and the sprouts were allowed to grow. These were all elliptical like the cherry, and made most wood on the two sides. It appeared to me that the trees made wood where it was most needed, on the sides where the strain of the wind came. Sometimes the eccentricity is produced by large branches or large roots on one side of the stem, and in other cases these seem to have little influence." This accords with the view of Mr. Herbert Spencer, who, in the appendix to his second volume of "Biology," gives the history of an interesting course of experiments "On Circulation and the Formation of Wood in Plants."
Notes on the British Arctic Expedition.—Of the two ships constituting the British Polar Expedition, the Discovery, Captain Stephenson, wintered at Cape Baird, latitude 81° 40'; and the Alert, Captain Nares, at Cape Union, latitude 82° 30'. The site of the supposed "Open Polar Sea" was found to be occupied by a rigid sea of ice, called the Paleocrystic Sea, or Sea of Ancient Ice. The thickness of this ice is enormous, varying from 80 to 120 feet. This Paleocrystic Sea is no doubt the accumulation of many years, or even of centuries. The lowest temperature experienced by the expedition was 104° Fahr. below freezing, which is 20° below the minimum observed by the Polaris Expedition. The sun was absent 142 days. A sled-party from the Alert planted the British flag in latitude 83° 20' 26"; but, as they had to hew a track through the exceedingly rough surface of this frozen sea, seventy-two days were spent in accomplishing the journey. Another party explored the coast-line westward for a distance of 220 miles. The most northerly point of the coast of Grant Land was found by this party to be Cape Columbia—latitude 83° 7', west longitude 70° 30'. The Greenland coast was explored by a party from the Discovery, and its most northerly point found to be in latitude 82° 50', west longitude 43° 30'; thence the coast trends in a southeastern direction. A good seam of coal was discovered near the winter-quarters of the Discovery. A brass tablet with the following appropriate inscription was fixed on the grave of the gallant American explorer, Captain Charles Francis Hall: "Sacred to the memory of Captain C. F. Hall, of the U. S. ship Polaris, who sacrificed his life in the advancement of science on November 8, 1871. This tablet has been erected by the British Polar Expedition of 1875, who, following in his footsteps, have profited by his experience."
Sexual Selection among the Monkeys.—Mr. Darwin, in his "Descent of Man," holds that the brilliant coloring of the face in the male mandrill, and of the posterior callosities in that and sundry other species of monkeys, is the result of sexual selection. He now, in a communication to Nature, brings forward some new observations on this subject made by Joh. von Fischer, of Gotha. Von Fischer finds that not only the mandrill, but the drill and three other kinds of baboons, which he names, also Cynopithecus niger, Macacus rhesus, and M. nemestrinus turn the hind-parts of their bodies, which in all these species is more or less highly colored, toward him when they are pleased, and toward other persons as a kind of greeting. Many other facts of a like nature are mentioned by Mr. Darwin, and then he expresses the opinion that "the bright colors, whether on the face or hinder end, or, as in the mandrill, on both, serve as a sexual ornament and attraction. Any-
