lated, that I should have been quite deceived, had I not seen that the fly was still upon the window. Accordingly I drew his attention to this fact, as well as to the absence of any thing upon the floor; and, when he saw that his hypocrisy had been detected, he slunk away under some furniture, evidently very much ashamed of himself."
Mechanical Action of Light.—It has been supposed that the rays of light, as distinguished from heat-rays, can produce no mechanical effects, such as repulsion and attraction; and the circumstance that these rays are unable to propel the arms of a vane suspended in vacuo has even been employed as an argument against the truth of Newton's emission theory of light. Mr. William Crookes, however, at a recent meeting of the London Royal Society, exhibited an apparatus which he calls "the radiometer," by means of which he proves that the luminous rays produce direct mechanical effects, after all the thermic rays have been strained out. The radiometer is described as consisting of four pith disks, fixed at the extremities of two crossed arms of straw balanced on a pivot at the point where the straws cross each other, so that they can spin round on the pivot. These pith disks are white on one of their sides and blackened on the other. The entire arrangement is inclosed in a glass bulb, from which the air is removed by means of a Sprengel pump. On being subjected to the action of light from which ninety-five per cent, of the heating rays had been strained out by means of an interposed plate of alum, the disks rotated with a speed little inferior to that when the heat-rays were allowed to mingle with the rays of light. And what is very singular, it is the blackened surface which is repelled by the luminous rays. Inasmuch as light is reflected by a white surface, and absorbed by a black, one should expect that in the experiment the white faces of the disks would rather be repelled. This anomaly Mr. Crookes does not attempt to account for, and he is content to let the facts speak for themselves, being confident that in due time the laws governing them will be made manifest.
It having been suggested by Prof. Osborne Reynolds that the movement of the little vane might be due to evaporation and condensation on the surface of the pith disks, Mr. Crookes showed that this was not the case He exhibited the very same effects with a lever-arm of platinum, suspended by an arm of platinum, the whole of which had been heated to redness again and again, during thirty-six hours of exhaustion by the Sprengel pump.
Prof. Huxley on the Amphioxus.—In a preliminary note upon the brain and skull of Araphioxus (the lancelet), Prof. Huxley shows that, although these organs are not fully differentiated in this animal, yet well-marked divisions of the nervous axis and spinal column exist which answer to the encephalon and cranium of the higher fishes. The homologies of the anterior pairs of nerves are worked out, and the skull is considered to be represented by the segments of the body which lie in front of the fifteenth, counting from before backward. The many points of resemblance in structure between the lancelet and the young form or larva of the lamprey (petromyzon) are insisted on, and it is suggested that Amphioxus should be regarded as the type of a new primary division of the class Pisces, to be called Entomocrania, as contrasted with all other known fishes, in which the primary cranial segmentation is lost, and for which the term Holocrania is proposed.
What Savages think of Twins.—In Africa, according to Dr. Robert Brown ("Races of Mankind"), the birth of twins is commonly regarded as an evil omen. No one, except the twins themselves and their nearest relatives, is allowed to enter the hut in which they first saw the light. The children are not allowed to play with other children, and even the utensils of the hut are not permitted to be used by any one else. The mother is not allowed to talk to any one not belonging to her own family. If the children both live till the end of the sixth year, it is supposed that Nature has accommodated herself to their existence, and they are thenceforth admitted to association with their fellows. Nor is this abomination of twin births restricted to
