FOOTNOTES:

[18] For a remarkable critical history of biological thought during this period, see Radl, ’09.

[19] Morley Roberts is a recent exception. See his interesting book, Warfare in the Human Body.

[20] Science, September 1921.

[21] See Thorndike, ’11.

[22] See J. S. Huxley, ’12, for a discussion of the grades of biological individuality.

[23] See, e.g., Wells, ’21, pp. 558, 666.

[24] See Roux, ’81, for a discussion of this important extension of Darwinism.

[25] See Thorndike, op. cit.; Washburn, The Animal Mind. New York, 1913.