BIOMETRIC IDEAS AND METHODS IN BIOLOGY:
THEIR SIGNIFICANCE AND LIMITATIONS
I.
The last fifteen years have witnessed the origin and development of what amounts to a new branch of biological inquiry, namely biometry. This subdivision of biological science which has within this period come to be practically a distinct and separate « fact » may fairly be said to have taken its origin at about the year 1895 in the pioneer investigations of Pearson and Weldon. In making this statement there is no intention of implying that there had not been important quantitative work of one kind or another in biology before 1895. There certainly had been a considerable amount of such work. It had, however, fallen in special and rather restricted fields. Most important in this earlier quantitative biology are probably to be reckoned the studies of the anthropologists. In this field the work of Quetelet and of Galton stands preeminent. The work of these men, and in particular that of Galton, indeed served in considerable degree as the stimulus for an extension of quantitative ideas and methods into other and broader fields of biology.
Nor was physical anthropology the only phase of biology which had been definitely cultivated along quantitative lines before 1895. Certain branches of physiology have long been highly developed in this direction. One thinks particularly in this connection of the study of the physiology of nerve and muscle. It is probably no exaggeration to say that so com-
