This book is a collection of a series of lectures on malariology held at the University of Palermo in 1945 by Professor Ascoli and his associates. Since 1936 Professor Ascoli has written widely on his concept of the malaria infection as a two phase process: a first (septicemic) phase, responsible for the acute episodes of the disease in which the parasites circulate and reproduce in the blood stream, and a second (focal) phase, in which the parasites perpetuate the infection by remaining in the red blood cells stationed in the ordinary blood reservoir organs (especially the spleen). This situation would be responsible for the occurrence of relapses and for the bad condition of the patient between acute episodes. The first phase responds to chemotherapy; the second does not. However, intravenous injection of increasing amounts of epinephrine hydrochloride, from 1/100 to 1/10 mg., over a variable period (twenty to thirty days)