The Nobel prize in medicine for 1908 has been given to Metchnikoff and Ehrlich, the full prize having been divided. Whatever the reasons and motives may have been that led the wise men in Stockholm thus to divide the prize, there is no question whatsoever but that in the opinion of those competent to judge of the value of the scientific work of Metchnikoff and Ehrlich, each has earned the undivided prize. . . .
Originally a Russian zoologist, Metchnikoff became our first great comparative pathologist. His chief credit is the establishment by extensive comparative studies of the occurrence of phagocytosis in all classes of animals and its significance in infections. In all animals the most striking phenomenon in the reactions to infection and injury seemed to him to be phagocytosis and hence arose the phagocytic theory of healing and immunity. This theory Metchnikoff and his followers defended with great skill and ingenuity against the violent attacks on it by the adherents of the humoral theory of immunity, especially in Germany. The resulting controversy proved a powerful stimulus to investigation and a degree of harmony has been reached as it has become clear, on the one hand, that cells are essential to the production of the antibodies that give to the fluids of the body their protective and healing properties, and, on the other hand, that the fluids of the body are essential to phagocytosis. In other words, neither theory alone accounts fully for the phenomena of healing and immunity, but both taken together go far toward furnishing a satisfactory explanation. Phagocytosis will ever be regarded as an important means of defense and healing, a few lingering, repetitive protests in Germany to the contrary notwithstanding. . . .