Calcinosis, wherever it appears, is no more than overloading of the conjunctive tissue with calcium. Arterial calcinoses are perhaps the type most frequently recognized : obliterating arteriopathy of middle aged and elderly subjects, arteritis in diabetics, Mönkeberg's arteriosclerosis. Venous calcinoses are either phleboliths, more rarely subcutaneous deposits, or atherocalcinosis of the inferior vena cava, or Cramer and Schilling's lesion. Subcutaneous calcinoses that appear to be nonvascular may give rise to some diagnostic problems. These concern the pathogenesis : calcium transfer by LERICHE and POLICARD, metaplasia of the conjunctive tissues and the elastic fibres, transformation of lipoproteins, hydraulic disturbances, Selye's calciphylaxia.