The extreme sensitiveness of the skin, the readiness with which its stimulation reverberates into the sexual sphere, clearly brought out by the present study, enable us to understand better a very ancient contest—­the moral struggle around the bath.  There has always been a tendency for the extreme cultivation of physical purity to lead on to the excessive stimulation of the sexual sphere; so that the Christian ascetics were entirely justified, on their premises, in fighting against the bath and in directly or indirectly fostering a cult of physical uncleanliness.  While, however, in the past there has clearly been a general tendency for the cult of physical purity to be associated with moral licentiousness, and there are sufficient grounds for such an association, it is important to remember that it is not an inevitable and fatal association; a scrupulously clean person is by no means necessarily impelled to licentiousness; a physically unclean person is by no means necessarily morally pure.  When we have eliminated certain forms of the bath which must be regarded as luxuries rather than hygienic necessities, though they occasionally possess therapeutic virtues, we have eliminated the most violent appeals of the bath to the sexual impulse.  So imperative are the demands of physical purity now becoming, in general opinion, that such small risks to moral purity as may still remain are constantly and wisely disregarded, and the immoral traditions of the bath now, for the most part, belong to the past.

SMELL.

I.

The Primitiveness of Smell—­The Anatomical Seat of the Olfactory Centres—­Predominance of Smell among the Lower Mammals—­Its Diminished Importance in Man—­The Attention Paid to Odors by Savages.

The first more highly organized sense to arise on the diffused tactile sensitivity of the skin is, in most cases, without doubt that of smell.  At first, indeed, olfactory sensibility is not clearly differentiated from general tactile sensibility; the pit of thickened and ciliated epithelium or the highly mobile antennae which in many lower animals are sensitive to odorous stimuli are also extremely sensitive to tactile stimuli; this is, for instance, the case with the snail, in whom at the same time olfactive sensibility seems to be spread over the whole body.[24] The sense of smell is gradually specialized, and when taste also begins to develop a kind of chemical sense is constituted.  The organ of smell, however, speedily begins to rise in importance as we ascend the zooelogical scale.  In the lower vertebrates, when they began to adopt a life on dry land, the sense of smell seems to have been that part of their sensory equipment which proved most useful under the new conditions, and it developed with astonishing rapidity.  Edinger finds that in the brain of reptiles the “area olfactoria” is of enormous extent, covering, indeed, the greater