Most clearly related to our present study are the previously reported observations of children made directly, during childhood, by trained investigators. The modern development of mental tests has now enabled psychologists to identify young children who deviate from average in the direction of superiority as regards selective thinking, and to follow their development for some years. Eventually, therefore, it will be known how to recognize those children who can become "great," and whether extreme deviation in mental tests is a basis of prophecy. BIBLIOGRAPHY 1. BINET, A. _Psychologie des grandes calculateurs et joieurs d'échecs. Hachette, Paris; 1894. 2. BRIMHALL, D. "Family Resemblances among American Men of Science," _American Naturalist_, Vol. 56 (1922) and Vol. 57 (1923). 3. CASTLE, C. S. "Statistical Study of Eminent Women." _Archives of Psychology_, Vol. IV, No. 27 (1913). 4. CATTELL, J. McK. "A Statistical Study of Eminent Men." _Popular Science Monthly_ (1903). 5. ------ "Families of American Men of Science." _Popular Science Monthly_, Vol. 86, pages 504-515 (1915). 6. CLARK, E. L. _American Men of Letters: Their Nature and Nurture_. Columbia University Press, New York; 1916. 7. COX, C. M. _The Early Mental Traits of Three Hundred Geniuses_. Genetic Studies of Genius: Vol. 2. Stanford University Press, Stanford University, California; 1926. 8. DAVIES, G. R. "A Statistical Study of the Influence of the Environment." _Quarterly Journal of the University of North Dakota_ (1914). 9. DE CANDOLLE, A. _Histoire des Sciences et des Savants depuis Deux Siècles_. Geneva, Switzerland; 1873. 10. ELLIS, HAVELOCK. _A Study of British Genius_. Hirst and Blackett, London; 1904. 11. GALTON, FRANCIS. _English Men of Science_. The Macmillan Company, London; 1874. 12. ------ _Hereditary Genius_. The Macmillan Company, New York, 1914. (Original edition, London; 1869.) 13. LEHMAN, HARVEY C. "The Creative Years in Science and Literature." _Scientific Monthly_, Vol. XLIII, pages 151-162 (1936). 14. LOMBROSO, C. _The Man of Genius_. Scott, London; 1895. 15. MIDDLETON, W. C. "The Propensity of Genius to Solitude." _Journal of Abnormal and Social Psychology_, Vol. 30, pages 325-332 (1935). 16. MITCHELL, F. D. "Mathematical Prodigies." _American Journal of Psychology_, Vol. 18, pages 61-143 (1907). 17. ODIN, A. _Genèse des Grands Hommes des Lettres Français Modernes_. Paris et Lausanne; 1895. 18. RASKIN, E. "Comparison of Scientific and Literary Ability: A Biographical Study of Eminent Scientists and Men of Letters of the Nineteenth Century." _Journal of Abnormal and Social Psychology_, Vol. 31, pages 20-35 (1935). 19. SCHUSTER, E. "The Promise of Youth and the Performance of Manhood." _Eugenics Laboratory Memoirs_, Vol. 3, pages 16 ff. London; 1907. 20. TERMAN, LEWIS M. "The IQ of Francis Galton in Childhood." _American Journal of Psychology_, Vol. 28, pages 209-215 (1917).