DR. GUSTAVE LE BON, a prominent psychologist, ethnologist and natural philosopher, was born at Nogent Le Notru, Eure-et-Loire, on May 7, 1841. He started his career as a medical officer in the French Army and served in the Franco-Prussian War of 1870-71, but afterwards gave up the practice of medicine and travelled extensively in Europe, Africa and Asia. In 1884 he was ordered by the Frendi Government to report on the Buddhist monuments in India. The results of his investigations were published in “La Civilisation de Flnde” (1884) and “Les Monuments de l'lnde” (1894). He is best known, however, for his works on psychology, especially “La Psychologic des foules” (1895), which went through twenty-seven editions and was translated into many foreign languages. He also wrote on psychology in relation to the French Revolution, the War of 1914-18, socialism and education. His chief contributions to natural philosophy consisted in his “Evolution de la matiere” (1905) and “Evolution des forces” (1907). An anatomical and mathematical study on variations in the size of the cranium won him a prize from the Paris Academy and the Anthropological Society of Paris. He was founder and for some years director of the Bibliotheque de philosophie scientifique. He died on December 14, 1931.