“ Quetelet's astronomical papers refer chiefly to shooting stars and similar phenomena. He organised extensive magnetical and meteorological observations, and in 1839 he started regular observations of the periodical phenomena of vegetation, especially the flowering of plants. The results are given in various memoirs published by the Brussels Academy, and in his works Sur le climat de la Belgique and Sur la physique du globe (the latter forms vol. xiii. of the Annales, 1861) . ”

“ In these works he shows how the numbers representing the individual qualities of man are grouped round the numbers referring to the “average man” in a manner exactly corresponding to that in which single results of observation are grouped round the mean result, so that the principles of the theory of probabilities may be applied to statistical researches on the subjects. ”

“ These ideas are further developed in various papers in the Bulletin and in his L'Anthropométrie, ou mesure des différentes facultés de l'homme (1871) , in which he lays great stress on the universal applicability of the binomial law,—according to which the number of cases in which, for instance, a certain height occurs among a large number of individuals is represented by an ordinate of a curve the binomial) symmetrically situated with regard to the ordinate representing the mean result (average height) . ”