Cellular Aspects of Immunology as Manifested in the Simonsen Reaction

Immunology has traditionally been concerned with two central topicsimmunity against pathogenic microorganisms and the nature and properties of antibodies. Both of course are, and will remain, immensely important but at the present time there can be little question that the problems of the origin, nature, and behaviour of the "immunologically competent cell" provide the centre of current interest in theoretical immunology. There are five sets of experimental findings that are chiefly responsible for that interest and which lay down the lines on which modern theories of immunity have been developed.