believe that dark pigment is essential to good hearing, as it certainly is to perfect vision. We can therefore understand why white cats with blue eyes are so often deaf; a peculiarity we notice more readily than their deficiency of smell or taste. If then the prevalence of white-coloration is generally accompanied with some deficiency in the acuteness of the most important senses, this color becomes doubly dangerous, for it not only renders its possessor more conspicuous to its enemies, but at the same time makes it less ready in detecting the presence of danger. Hence, perhaps, the reason why white appears more frequently in islands where competition is less severe and enemies less numerous and varied. Hence, also, a reason why albinoism, although freely occurring in captivity, never maintains itself in a wild state, while melanism does. The peculiarity of some islands in having all their inhabitants of dusky colors--as the Galapagos--may also perhaps be explained on the same principles; for poisonous fruits or seeds may there abound, which weed out all white or light-colored varieties, owing to their deficiency of smell and taste. We can hardly believe, however, that this would apply to white-colored butterflies, and this may be a reason why the effect of an insular habitat is more marked in these insects than in birds or mammals. But though inapplicable to the lower animals, this curious relation of sense acuteness with colors may have had some influence on the development of the higher human races. If light tints of the skin were generally accompanied by some deficiency in the senses of smell, hearing, and vision, the white could never compete with the darker races, so long as man was in a very low and savage condition, and wholly dependent for existence on the acuteness of his senses. But as the mental faculties become more fully developed and more important to his welfare than mere sense acuteness, the lighter tints of skin, and hair, and eyes, would cease to be disadvantageous whenever they were accompanied by superior brain power. Such variations would then be preserved; and thus may have arisen the Xanthochroic race of mankind, in which we find a high development of intellect accompanied by a slight deficiency in the acuteness of the senses as compared with the darker forms. AN INVOLVED ACCIDENT.