including in the differentiation of ectoderm from endoderm begins. ‘Therefore we 8 E.G. Conklin, Heredity and Evolution (1910); H. Piéron, L Évolution de la Parthénogenése Expérimen- tale,” Bull. Scientifique de la Ceramica de Alcora (Madrid, 1919); C. N. Bruce, J. C. B. Cochran installed there a dividing line came. For frankly and in 1917 and cd. 9002 of 1918); Jan. 1 1912. The influence of his