Open main menu

Page:Popular Science Monthly Volume 44.djvu/294

This page has been proofread, but needs to be validated.

in the pose of Egyptian drawings of the human figure is that it is an impossible combination according to our ideas. We see the face in profile, the eye full length, the chest in front view, and the legs sidewise. But before we condemn this as contrary to Nature, it is well, as Prof. W. M. Flinders Petrie suggests, to see what the attitude of a modern Egyptian is, and how far our notions are correct. To avoid all ideas of posing for the subject, he selects the figure of a boy from a large group that was photographed without any special aim by a Cairo dealer. In the kneeling figure are seen the profile of the face, the eye full, the chest in front view, and the legs sidewise. Everything that we have heard condemned as unnatural and impossible in the ancient sculpture is seen in the modern native, without any constraint, when simply taking an easy position. This shows what is the true ideal of the conventional Egyptian pose; it is a three-quarters view, modified by the omission of the much foreshortened parts beyond the profile—a simplification which was essential to an outline system of representation.


Variety in the Eyes of Animals.—It is hard, in studying some of the lower animals, to determine whether they have a proper sense of vision. They can all recognize light and distinguish it from darkness; but that is probably all the sight that a few organisms possess. In such creatures as earthworms, for instance, the whole skin is supposed to be sensitive to light; and there is some evidence that they have a choice between colors. Mollusks have eyes of various qualities: those of the snail distinguishing light from darkness; those of the cuttlefish very highly developed; the unique and curious eyes of the nautilus; and the two kinds of eyes of the onchidium. Some of these animals possess the power of restoring their eyes, as well as other lost members, when they are cut off. Great differences appear in the organs of sight of crustaceans. They are of all sorts, from a simple eye-spot in some species up to two compound eyes on a movable eye-stalk (as in the crab and lobster), with complete optical apparatus; and some have both simple and compound eyes. Most insects have two kinds of eyes; the large compound eye, one on each side of the head; and the ocelli, or simple eyes, of which there are geuerally three, placed in a triangle between the other two. The compound eyes are complex in structure, consisting of a number of hexagonal facets,—each with its system of nerves. It is not known whether the combination forms one aggregate eye, or whether each facet is an eye. Many insects have thousands of these facets some beetles as many as twenty-five thousand. The vision of scorpions, though they have six eyes, is imperfect; and that of spiders, equally well provided as to the number of ocelli, is not much better. The dexterity and unerring aim with which many reptiles catch their insect food in the air proves that they have very keen vision. The chameleon has the additional faculty of moving its eyes independently of each other, so that it can look up with one eye while looking down with the other, backward and forward, or in other different directions. The eyes of deep-sea fish are very varied: some have no eyes or sight; some have greatly enlarged eyeballs; and others are provided with phosphorescent processes or spots. Birds and many of the smaller mammals have very acute vision, while that of the lai-ger animals is very much like our own.


Co-operation in Nature.—That crude competition is the universal law of Nature, while combination is the invention of the mind of man, is doubted by Mr. Henry Farquhar. The position, he says, is "difficult to reconcile with even the most hasty consideration of ruminants feeding in herds, where, instead of a tumultuous crowding for the occupation of the best places, we see some individuals taking posts in which they can be of service in warning the whole herd of impending danger—or of the wolves that prey upon them in co-operating packs. It is not to be rashly claimed that mind. . . is absent from the conduct of the ant and her colonies; but surely their example is convincing evidence that the lesson of the economic superiority of concert over cutthroat individual competition is one that has been well taught and learned in realms of Nature widely sundered from ours. . . . If not with man as a self-conscious being, where in the course of evolution does an implicit recognition of the wastefulness of indiscriminate competition