54 THE POPULAR SCIENCE MONTHLY. 



Eenal force, degrees. . . 180-190 200 



No. of men in 64 6 1 



Binom. coeff 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 compara- 

 tively simple case, that of the stature-curve. Here a curve approxi- 

 mating 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 JM. 

 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 accept- 

 ed the theory of the mean, or central standard, as a basis for the com- 

 parison 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 reason- 

 able 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 accurate- 

 ly admeasured proportions he may approximate very closely to a cen- 

 tral race-type. 1 It is not necessary to dwell on the obvious difficulties 



1 Thus General Lefroy's measurements of thirty-three Chippewa Indians (" Journal 

 *f 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 nu- 

 merical law of variation in the tribe, the series of groups from five ft. 3 in. to 5 ft. 11 in 

 being as follows : 1, 1-J, U, 6, 8, 4, 4 J, 3, 1. 



