In criticism of this conclusion of Fabre, however, we must again draw attention to the fact that in the case of the Greater Peacock he found that a plug of cotton-wool was sufficient to prevent the emanation leaving the immediate neighbourhood of the female, a circumstance strongly in favour of some material exhalation which was caught and held by the cotton-wool filter. Again, in the case of the Banded Monk, the suggestion of odour is unmistakable in the tainting, as it were, of substances in her vicinity with her emanation. Further, if the guide to the males were something like a luminous undulation we should expect that, like the Bolboceros beetle and the badger, there would have been no blundering and going astray; they would have precipitated themselves straight on to the female, or as near to her as they could get. Moreover, although we are ourselves unable to detect any odorous emanation, may not our inability be due simply to the fact that our olfactory hairs are not susceptible to this particular stimulus? It may be of the same nature as odour, and yet we may be unable to perceive it, just as the moths themselves seemed anosmic to what we would call the stenches Fabre filled his room with. These critical questions seem to me to be difficult to answer. Nevertheless, our imagination is certainly staggered by the fact of a tiny creature like a moth being able to disseminate in the immensity of atmospheric space an odour capable of perception at such great distances as a mile or a mile and a half. Hero, with the Great Peacock’s power, could have summoned Leander from a hundred miles away. Apart, however, from such considerations for and against his opinions, one of the modern theories of odour, and of odour belonging to Fabre’s first, or material, order, is, as we shall see later on, that even it is a vibratory and not a material quality. But leaving that development aside, and admitting for the moment the validity of Fabre’s contentions, I am bold enough to ask: Are we human beings so ignorant of the second domain of olfaction as he supposes? Is it true that we are, as he says, lacking in the equipment necessary for the exploration of that mysterious region? To answering these questions we shall presently address ourselves. In the meantime, I may forestall what I shall then say by remarking that I count it a very remarkable circumstance, if not, indeed, a significant coincidence, that, before I had become acquainted with Fabre’s writings, I had, considering the phenomena of human olfaction and psychology alone, actually asked myself the same question as he asks, and had come to very much the same conclusion. CHAPTER III OLFACTORY MEMORY The predominant special senses in man are vision and hearing, olfaction occupying a quite unimportant position in the scale.