Exploring the morphology of renal disease through the use of immunofluorescent and electron microscopy, this study discusses basic principles of immunology, focusing on glomerulonephritis, dysproteinaemic nephropathy, and the pathogenesis of most forms of renal disease, including macroglobulinaemia, cryoglobulinaemia, focal glomerulosclerosis, IgA disease, and dense deposit disease.