The researches of the physiological laboratories have enlarged in every direction our knowledge of the great functions of life—digestion, assimilation, circulation, respiration, and excretion. Perhaps in no department have the results been more surprising than in the growth of our knowledge of the functions of the brain and nerves. Not only has experimental science given us clear and accurate data upon the localization of certain functions of the brain and of the paths of sensatory and of motor impulses, but it has opened an entirely new field in the diagnosis and treatment of the diseases of these organs, in certain directions of a most practical nature, enabling us to resort to measures of relief undreamed of even thirty years ago. The study of physiology and pathology within the past half-century has done more to emancipate medicine from routine and the thraldom of authority than all the work of all the physicians from the days of Hippocrates to Jenner, and we are as yet but on the threshold. THE GROWTH OF SPECIALISM The restriction of the energies of trained students to narrow fields in science, while not without its faults, has been the most important single factor in the remarkable expansion of our knowledge. Against the disadvantages in a loss of breadth and harmony there is the compensatory benefit of a greater accuracy in the application of knowledge in specialism, as is well illustrated in the cultivation of special branches of practice. Diseases of the skin, of the eye, of the ear, of the throat, of the teeth, diseases of women and of children, are now studied and practised by men who devote all their time to one limited field of work. While not without minor evils, this custom has yielded some of the great triumphs of the profession. Dentistry, ophthalmology, and gynæcology are branches which have been brought to a state of comparative perfection, and very largely by the labors of American physicians. In the last-named branch the blessings which have been brought to suffering women are incalculable, not only as regards the minor ailments of life, but in the graver and more critical accidents to which the sex is liable.