[98] The importance of gray matter in mental processes has evidently been greatly overestimated, for it has been found to be thicker in the brains of negroes, murderers and ignorant persons than it was in the encephalon of Daniel Webster. It is also much thicker in the brains of dolphins, porpoises and other cetaceans than it is in the most intellectual of men.
[99] The Descent of Man, Vol. I, p. 145, London, 1871.
[100] The brain of Sónya Kovalévsky was not weighed until it had been four years in alcohol. Prof. Gustaf Retzius then wrote an elaborate account of it and estimated that its weight, at the time of Sónya's death, was 1385 grams. The brain-weight of her illustrious contemporary, Hermann von Helmholtz, was 1440 grams. But when the body-weights of these two eminent mathematicians are borne in mind—Sónya was short and slender—it will be seen that the relative amount of brain tissue was greater in the woman than in the man. Cf. Das Gehirn des Mathematikers Sónja Kovaléwski in Biologische Untersuchungen, von Prof. Dr. Gustaf Retzius, pp. 1-17, Stockholm, 1900.
[101] The reader who desires more detailed information respecting the brain-weights of men and women of various races and the relation of brain-weight to intelligence may consult with profit the following works and articles: Mémoires d'Anthropologie de Paul Broca, 5 Vols., Paris, 1871-1888; Alte und Neue Gehirn Probleme nebst einer 1078 Falle umfassenden Gehirngewichstatistik aus den Kgl. pathologisch-anatomischen Institut zu München, von W. W. Wendt, München, 1909; Gehirngewicht und Intelligenz, by Dr. F. K. Walter, Rostok, 1911; Gehirngewicht und Intelligenz, by Dr. J. Dräseke, Hamburg, in Archiv für Rassen und Gesellschafts Biologe, pp. 499-522, 1906; Brain Weights and Intellectual Capacity, by Joseph Simms, M. D., in the Popular Science Monthly, December, 1898, and The Growth of the Brain, by H. H. Donaldson, London, 1895.
[102] "Quand on songe à la différence qui sépare de notre temps l'éducation intellectuelle de l'homme de celle de la femme, on se demande si ce n'est pas cette influence qui rétrécit le cervaux et le crane féminins, et si, les deux sexes étant livres a leur spontanéité, leur cervaux ne tendraient pas à se ressembler, aussi qu'il arrive chez les sauvages." Bulletin de la Société d'Anthropologie, p. 503, Paris, July 3, 1879.
[103] Times, London, July 8, 1874. Cf. Chap. XVII, on "Adolescent Girls and Their Education," in Adolescence, Vol. II, by G. Stanley Hall, New York, 1904.
[104] The Study of Science by Women in the Contemporary Review for March, 1869.
[105] Die Akademische Frau. Gutachten hervorragender Universitäten-professoren, Frauenlehrer und Schriftsteller über die Befähigung der Frau zum wissenschaftlichen Studium and Berufe herausgegeben von Arthur Kirchhoff, Berlin, 1897.
[106] "Ich komme beim Nachdenken hieruber zu der Ueberzeigung, dass kein Gott und keine Religion, kein Herkommen und kein Gesetz, aber ebensowenig die Wissenschaft uns das Recht erteilen, in dieser Beziehung zwischen dem mannerlichen und weiblichen Geschlect einen principiellen Unterschied zu statuiren." Die Akademische Frau, p. 41.
[107] The Subjection of Women, p. 91, London, 1909.