Page:Popular Science Monthly Volume 14.djvu/712

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THE POPULAR SCIENCE MONTHLY.

should not be heard outside of the nursery. It may be added that the "rice-grains" in the collection presented to Mr. Buckland are identified by Mr. Owen as marine shells of the genus Cypræa, the end or apex of each being carefully filed or ground off to represent the effect of having been fed on by the pearls.

 

Survival of Serious Brain Injury in a Pigeon.—A remarkable case of recovery of all the faculties in a pigeon from which four fifths of the upper portion of the cerebrum had been removed, is recorded by Dr. J. H. McQuillen, in the "Proceedings" of the Academy of Natural Sciences of Philadelphia. The author, who is Professor of Physiology in the Philadelphia Dental College, on February 4th of last year, exposed the cerebrum of a pigeon, and cut out four fifths of the upper portion in slices: this he did in illustrating to his class the fact that the sensorium thus exposed could be cut pinched, or burned, without any sign of pain on the part of the animal. The usual phenomena followed, viz., profound stupor, the bird standing motionless on the table, with eyes closed, head sunk between the shoulders, and feathers ruffled. At the close of the demonstration, this pigeon was given to Professor Emily White, M. D., of the Women's Medical College, with the request that an effort should be made to keep the bird alive, and ascertain whether the mutilated organ would regain its functions. In March a note was received from Professor White, in which she stated that the pigeon had apparently recovered all its faculties. "He is," it was added, "perhaps less excitable than normal, and seems perfectly tame, but bright." Dr. McQuillen at once sent for the bird, and observed with surprise the complete recovery of the voluntary movements of walking and flying, the power of feeding itself and drinking as usual, and the general manifestations of intelligence. The bird continued in full possession of its faculties for six months, and then was put to death and an examination made. On removing the scalp a fibrous structure, analogous to pericranium, was found, occupying the place from which the bone had been removed in making the vivisection. Cutting this away, a small amount of fluid escaped, and the cranial cavity thus exposed was found occupied by a white substance resembling the cerebral structure that had been removed six months before. Placing a section of the upper portion of this, which had been stained with hematoxyline, under the microscope, a number of bipolar cells characteristic of the gray structure were observed.

 

Pigments of the Hair.—By treating with dilute sulphuric acid different kinds of human hair, Mr. H. C. Sorby obtains three distinct pigments, a red, a yellow, and a black. The red pigment is probably convertible by oxidation into the yellow. Very red hair is characterized by the presence of the red constituent unmodified by any other coloring substance; golden hair has less of the red and more of the yellow pigment; in sandy-brown hair the black and red constituents are associated with a large proportion of the yellow; in dark-brown hair the black pigment is present in larger quantity, while in black hair this dark substance predominates over the rest. Singularly enough, Mr. Sorby found in the hair of a negro about the same proportion of the red pigment as in the very red hair of a European. If in this case the development of the black pigment had been checked by any cause, he would have presented the curious spectacle of a red-headed negro.

 

Wallace's Theory of Zoölogical Derivation.—To illustrate Wallace's theory of the derivation of all animals from the north, a writer in "Nature" designed a map of the world on a polar projection, the northern hemisphere being projected somewhat beyond the southern tropic. This map clearly shows how the land-surface of the globe is built around the pole, and exhibits the extremities of America, Africa, and Australia, extending into the great ocean. If, now, the subdivisional regions (zoölogically) of each of these three great projections, and of the whole, be marked in colors, a succession of zoölogical strata (so to speak) appears. By carrying an ideal section from the supposed center of creation in the north through either of these three great extremities, and thence to the nearer and afterward the more remote of their dependencies, we pass in