other features and habits of different nations, but we pass to the consideration of a few special qualities. We are accustomed to distinguish our friends and acquaintances by their individual peculiarities, and we think we find very marked differences between them. Every man has his peculiarities of stature, girth, weight, color of hair, skin, and eyes, proportion between his limbs, strength, and pulse, but they all disappear, as Quetelet and others have shown, in the aggregate. The margin of variations in the individual traits of men is shown, by the measurements which these authors have applied to large groups, to be really very small. Among large masses of the population of a land as a whole, we find the same relative proportions of large, small, and middle-sized men, and constant relations in the number of thin, delicate, and bandy-legged persons, Falstaffs, strong and weak, quick tempered and cool-blooded. The same is the case with the color of the hair, eyes, and skin, as Virchow has shown in Germany and Bertillon in the schools of France. Such a constancy in these traits has been shown on all the points hitherto inquired into, that we are able to draw similar conclusions on questions of race and nationality from these anthropological researches to those which the geologist deduces from the strata concerning the age of the formation.
Even those afflictions which we regard and lament as purely casual visitations on some families, such as blindness and deaf-mutism, exhibit a remarkable constancy of prevalence in whole societies. It may be a sufficient illustration of this to mention the striking fact that several computations of the number of persons suffering from these defects in Austria-Hungary and the German Empire, made independently of each other, at different times, and in different ways, have given the same numerical results; and that the numbers in other states are curiously near to those in the two mentioned, often differing only by a decimal. Although there are groups of states in which somewhat different ratios prevail, the frequent recurrence of the same average per ten thousand inhabitants, in a whole series of states, and for different decades in time, justifies the assumption that some law of proportion prevails, and forbids our supposing that the number is merely an affair of accident. On the basis of a number of coincidences of this kind, Quetelet constructed his ideal of the "average man," as a general standard by which to estimate the conforming proportion of the aggregate, and compare the individual with the type.
From the natural peculiarities, from the compositional structure of social bodies, we go a step further to their vital activities, their real physiology. Henceforth we may consider the curious variances in human generations, formerly regarded as accidental and voluntary combinations, as subject to a strict law. Within the circle of our acquaintance are childless families, and families that are blessed with hosts of children; families with all boys, and families with all girls; some strangely assorted marriages; men of extraordinary age, while we