always have a prominent place in the history of endocrinology or the science that deals with the glands that secrete inwardly, a subject that already has a vast and rapidly growing literature, with an essentially new body of facts and insights and, at its present stage of development, yet far more precious hopes and expectations of great discoveries just ahead. Some of the many commercial products of testicular juices, so very difficult to prepare in a form that can be preserved, were for many years widely used and the best known of these, Pohl’s spermine preparations, are still more or less in demand. But despite Brown-Séquard’s enthusiastic belief in his age-deferring cure, it lapsed from general attention, partly because the initial expectations were too high, until a very few years ago when the problems it had suggested were approached in a new way by a few investigators whose results have not only a high value in themselves but give promise of yet more important and definite subsequent discoveries--and that despite the conservatism and criticism that all efforts to deal scientifically and fundamentally with human sex problems always encounter. Professor Eugene Steinach, who founded a laboratory of comparative physiology at Prague and was later made director of the biological institute at Vienna, continued to work there until his institute, for which Roux and others have solicited contributions from men of science, to have it opened again, was closed by the war. He began to publish his epoch-making results in 1910. In spring frogs brought to his laboratory he found 8 per cent impotent and also that testicular injection from normal frogs seemed to restore or intensify the embracement impulse and the strength of the forelegs.[180] The effect lasted, however, only a few days. Nevertheless he suggests that in borderline cases it might permanently restore fertility. The same process in castrated frogs showed the same effect, only in much less degree, and the injection of substance from the cerebro-spinal centers of these activities seemed to have a certain but very slight effect upon the sex nature.