Fishes, too, though they may have snouts, have not noses, because they breathe by gills. In truth, it seems that the nose was a very late and high acquisition, almost the finishing touch of the perfected animal form. And incidentally this leads us to notice what a great step was taken in evolution when the breathing holes were brought up to the region of the mouth. For the sense of taste is necessarily situated in the mouth, and the sense of smell is in close alliance with it. The mouth tastes food dissolved in the saliva during the process of mastication, and the primary use of the sense of smell is to detect and analyse beforehand the small particles given off by food and floating in the atmosphere.
A good many years ago, when the late Sally chimpanzee was the darling of the Zoological Gardens in Regent's Park, I watched her eating dates. She was an epicure, and always peeled each date delicately with her preposterous lips before eating it, and during the process she would apply the date to her nose every second to test its quality or enjoy its aroma. The action was indescribably comical, but what would it have been if her nostrils had been situated among her ribs? Imagine a mantis, for example, as he chews up a fly, lifting one of his wings and applying it to his flanks to see if it smells gamey. That is where some naturalists believe that the sense of smell is situated in insects. Others, however, think, with reason, that it is in the antennae or mouth. Nobody knows; the senses of the lower animals seem to be stuck about all parts of the body.
But, even if the sense of smell is at the mouth, how limited must its usefulness be when it can only deal with substances that are held to it! A new era dawned when the passages by which the breath of life unceasingly comes and goes were transferred to the region of the mouth also. The nerves of smell quickly spread themselves over the lining membrane of those passages and became warders of the gate, challenging every waft of air that entered the body and examining what it carried. Thenceforth this region comprising the mouth, nostrils and surrounding parts holds a new and high place in the economy of the body, for the headquarters of the intelligence department are located there, and all the faculties of the brain converge on that point. Of course, the eyes and ears claim a share, but they are not far off.
Now it is being recognised more and more clearly by medical and physiological science that when the mind is much directed to any part of the body it exercises an influence in some way not understood on the flow of blood to that part to a degree which may seriously affect its functions and even its growth. When a person is suffering from any nervous affection, from heart disease, or even from weakness of the eyes, it is of the utmost importance to keep him from knowing it if possible, for if he knows it he will think about it, and that will inevitably aggravate it. This principle is well recognised in systems of physical culture. And surely it is impossible that so much intelligence should pass through that one sensitive region of the body which we are considering without affecting its growth and structure. Every muscle in it becomes quick to respond to various sensations in different ways, till the very recollection of those sensations will excite the same response.
Nay, we may go further. The mental emotions excited by those sensations will be expressed in the same way. For example, the sense of smell is peculiarly effective in exciting disgust. Anything which does violence to the sense of hearing exasperates, but does not disgust. If a man practises the accordion all day in the next room you do not loathe him, you only want to kill him. But anything that stinks excites pure disgust. Here you have the key to the fact that disgust and all feelings akin to it, disdain, contempt and scorn, express themselves through the nose. Darwin says that when we think of anything base or vile in a man's character the expression of the face is the same "as if we smelled a bad smell." This is an example of the temporary expression of a passing emotion, and there are many others like it. But each of us has his prevailing and dominant emotions which constitute the habitual attitude of his mind. And by the habitual indulgence of any emotion the features will become habituated to the expression of it, and so the set of our features comes at last to express our prevailing and dominant emotions; in other words, our character.
But let us return to the evolution of the nose. In these days of universal "Nature study" nobody need be told that the practice of breathing through the nostrils was introduced by the amphibians and reptiles. The former (frogs and toads) take to it only when they come of age, but lizards, snakes and all other reptiles do it from infancy. But the nose is not yet. That is something too delicate to come out of a cold-blooded snout covered with hard scales. Birds, too, by having their mouth parts encased in a horny bill seem to be debarred from wearing noses. And yet there is one primeval fowl, most ancient of all the feathered families, which has come near it. I mean the apteryx, that eccentric, wingless recluse which hides itself in the scrub jungles of New Zealand. Its nostrils, unlike those of every other bird, are at the tip of its beak, which is swollen and sensitive; and Dr. Buller says that as it wanders about in the night it makes a continual sniffing and softly taps the walls of its cage with the point of its bill. But the apteryx is one of those odd geniuses which come into the world too soon, and perish ineffectual. Its kindred are all extinct, and so will it be ere long.
