CHAPTER II
THE SENSE OF OLFACTION IN LOWER ANIMALS
Olfaction is generally felt to be the lowest, the most animal, of the senses, so much so that in polite society it is scarcely good manners to mention smells, and I am well aware of the risks I run in writing a book on the subject. And yet this feeling is by no means false modesty, because it is, first and foremost, to the animal in us that smell makes its appeal. None of the other senses brings so frankly to notice our kinship with the brute.
Olfaction is, indeed, one of the primitive senses of animal life. And in man, as it happens, while vision has constructed for itself a highly complicated camera-like end-organ, and hearing has produced an apparatus even more elaborate, the olfactory organ, on the other hand, remains primitive, its essential structure having undergone no apparent evolutionary change from the simplest and earliest type.
This, perhaps, is scarcely the proper way of expressing the situation, Evolutionary change has, as a matter of fact, occurred, but it reaches
