THE POPULAR SCIENCE MONTHLY.
|Renal force, degrees||180-190||200|
|No. of men in 64||6||1|
In the various numerical examples here given, the element of age is not introduced, the ages of the individuals being calculated or taken as uniform. The problem of variation of numerical distribution of a population at different ages is treated by M. Quetelet in a comparatively simple case, that of the stature curve. Here a curve approximating to a parabola is laid down, the ages of man from birth onward being measured along its axis; each double ordinate of this curve forms the base on which a binomial curve is erected perpendicularly, the vertices of these curves forming a curve of mean stature, of the nature of a curve of mortality ("Anthropom.," p. 264). How far M. Quetelet may succeed in his contemplated purpose of carrying his method from the physical into the intellectual and moral nature of man, it is premature to judge.
Without entering into the more intricate and difficult problems opened by this theory of central types, it is evident that the bearing of its main conception on the problems of anthropology and biology in general is highly important. Some able anthropologists have accepted the theory of the mean, or central standard, as a basis for the comparison of races, but this line of research is still in its infancy. In M. Quetelet's last volume, a principle is worked out which serves as a bridge between the old and new methods. His experience is that, in a well marked population, no extraordinary number of observations is required for the determination of the mean man. In former ages, one result of the national type being so preponderant in number and so easily recognizable was, that the bodily measurements of any man of ordinary stature and proportions could be trusted to give, with reasonable accuracy, the standard measures of the nation, such as the foot, cubit, fathom, etc. In the same manner M. Quetelet finds a small number of selected individuals sufficient for ascertaining the standard national proportions of the human body, male and female, from year to year of growth; his tables, founded for the most part on Belgian models, are given in an appendix. This method is applicable to the purposes of general anthropology. Thus a traveller, studying some African or American race, has to select by mere inspection a moderate number of typical men and women, by comparison of whose accurately admeasured proportions he may approximate very closely to a central race type. It is not necessary to dwell on the obvious difficulties
- Thus General Lefroy's measurements of thirty three Chippewa Indians ("Journal of the Ethnological Society," vol. ii., p. 44, 1870) are sufficient to determine the stature of the mean man as about 5 ft. 1 in., the number of individuals in this maximum group being 8. It is even possible to guess from this small number of measurements the numerical law of variation in the tribe, the series of groups from five ft. 3 in. to 5 ft. 11 in being as follows: 1, 1½, 2½, 6, 8, 4½, 4½, 3, 1.