Edwin Grant Conklin (1863 1952) was a U.S. biologist and zoologist, born at Waldo Ohio, and educated at Ohio Wesleyan and Johns Hopkins universities. He was professor of biology at Ohio Wesleyan (1891-94) and professor of zoology at Northwestern (1894-96), the University of Pennsylvania (1896-1908), and Princeton (after 1908). He became co-editor of the Journal of Morphology, the Biological Bulletin, and the Journal of Experimental Zoology. He was president of the American Society of Naturalists in 1912 and president of the American Association for the Advancement of Science in 1936. The lectures which constitute this volume were given at the University of North Carolina in May, 1920, under the terms of the "John Calvin McNair Lectureship on the mutual bearings of science and religion upon each other." One or two of them were also delivered at Northwestern University, Mt. Holyoke College, Western University, and the University of Texas. The topic chosen for this series is one in which the bearings of science upon religion are most vital, namely, the origin and destiny of the human race. I shall attempt to present certain conclusions of science regarding the evolution of man, and shall venture to draw from these conclusions certain in