Through the initiative of Sir Francis Galton, as Dr. Myers points out, anthropometry has begun to investigate other problems which must ultimately be of ethnological interest; and he has opened out the whole subject of heredity, which eventually must enter into every branch of physical anthropology. The followers of Mendel are at present laying a foundation upon their experiments with plants and animals. At present very little attention has been paid by them to man; nor, probably, can much be attempted until more precise data are available. Lamentably little is known with accuracy about the physical and psychical effects of the mixture of different human types, and it is yet to be determined how far the admitted unsatisfactory character of many half-caste populations is due to physiological or sociological causes. There is a great dearth of sufficiently numerous and reliable observations and statistics concerning the effect of the environment upon small or large groups of human beings—a problem to which Professor Ridgeway devoted his last presidential address to the Royal Anthropological Institute (1910). It is often important that the physical fitness of people should be tested, in order to see how they stand in relation to other people, and to discover any physical imperfections. Especially is this desirable in the case of children; and the government inspection of school children, though inadequate, is a step in the right direction. By such means early inclinations to various defects are discovered and prevented, and valuable statistics are obtained which can not only be utilised for comparative purposes, but may form a basis for future legislation. It is also a matter of importance to determine whether certain imperfections are due to diseased, abnormal, or other undesirable factors in their parentage; or whether they are the results of unfavourable subsequent conditions. But in order that comparisons can be made, it is necessary to make similar investigations on the normal, capable, and healthy population. Another branch of investigation was undertaken mainly for the identification of criminals, and consisted in certain measurements selected by M. Alphonse Bertillon, supplemented by photographs and a record of individual peculiarities. The practical value of this method of identification in France was demonstrated by its immediate results. Criminals began to leave off aliases, and numbers of them flocked to England. Finger-prints as a means of identification were first discovered by Purkenje, the Breslau physiologist (1823), who utilised them for classification. Sir William Herschel, of the Indian Civil Service, adopted the method in Bengal, and now methods introduced by Sir Francis Galton are in use in India, England, and elsewhere, having in most cases supplanted the Bertillon system. ------------------------------------------------------------------------ CHAPTER III.