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.