[Sidenote: The custom of mutual avoidance between near relations has probably had the effect of checking the practice of inbreeding.] Viewed from this standpoint the customs of ceremonial avoidance among savages assume a serious aspect very different from the appearance of arbitrariness and absurdity which they are apt to present to the civilized observer who does not look below the surface of savage society. So far as these customs have helped, as they probably have done, to suppress the tendency to inbreeding, that is, to the marriage of near relations, we must conclude that their effect has been salutary, if, as many eminent biologists hold, long-continued inbreeding is injurious to the stock, whether animal or vegetable, by rendering it in the end infertile.[95.1] However, men of science are as yet by no means agreed as to the results of consanguineous marriages, and a living authority on the subject has recently closed a review of the evidence as follows: “When we take into account such evidence as there is from animals and plants, and such studies as those of Huth,[95.2] and {96} the instances and counter-instances of communities with a high degree of consanguinity, we are led to the conclusion that the prejudices and laws of many peoples against the marriage of near kin rest on a basis not so much biological as social.”[96.1] Whatever may be the ultimate verdict of science on this disputed question, it will not affect the result of the present enquiry, which merely affirms the deep and far-reaching influence which in the long course of human history superstition has exercised on morality. Whether the influence has on the whole been for good or evil does not concern us. It suffices for our purpose to shew that superstition has been a crutch to morality, whether to support it in the fair way of virtue or to precipitate it into the miry pit of vice. To return to the point from which we wandered into this digression, we must leave in suspense the question whether the Australian savages were wise or foolish who forbade a man under pain of death to speak to his mother-in-law. [Sidenote: Other examples of the severe punishment of sexual crime.] I will conclude this part of my subject with a few more instances of the extreme severity with which certain races have visited what they deemed improper connexions between the sexes.