[100] Valentin: Archiv f. d. gesammt. Physiol., 1873, p. 458. Stirling: Leipzig Acad. Berichte, 1875, p. 372 (Journal of Physiol., 1875). J. Ward: Archiv f. (Anat. u.) Physiol., 1880, p. 72. H. Sewall: Johns Hopkins Studies, 1880, p. 30. Kronecker u. Nicolaides: Archiv f. (Anat. u.) Physiol., 1880, p. 437. Exner: Archiv f. die ges. Physiol., Bd. 28, p. 487 (1882). Eckhard: in Hermann's Hdbch. d. Physiol., Bd. I, Thl. ii, p. 31. François-Franck: Leçons sur les Fonctions motrices du Cerveau, p. 51 ff., 339.--For the process of summation in _nerves_ and _muscles_, cf. Hermann: _ibid._ Thl. i, p. 109, and vol. i, p. 40. Also Wundt: Physiol. Psych., i, 243 ff.; Richet: Travaux du Laboratoire de Marey, 1877, p. 97; L'Homme et l'Intelligence, pp. 24 ff., 468; Revue Philosophique, t. xxi, p. 564. Kronecker u. Hall: Archiv f. (Anat. u.) Physiol., 1879; Schönlein: _ibid._1882, p. 357. Sertoli (Hofmann and Schwalbe's Jahres-bericht), 1882, p. 25. De Watteville: Neurologisches Centralblatt, 1883, No. 7. Grünhagen: Arch. f. d. ges. Physiol., Bd. 34, p. 301 (1884). [101] Bubnoff und Heidenhain: Ueber Erregungs- und Hemmungsvorgänge innerhalb der motorischen Hirncentren. Archiv f. d. ges. Physiol., Bd. 26, p. 156 (1881). [102] Archiv f. d. ges. Physiol., Bd. 26, p. 176 (1881). Exner thinks (_ibid._ Bd. 28, p. 497 (1882)) that the summation here occurs in the spinal cord. It makes no difference where this particular summation occurs, so far as the general philosophy of summation goes. [103] G H. Lewes: Physical Basis of Mind, p. 479, where many similar examples are given, 487-9. [104] Romanes: Mental Evolution in Animals, p. 168. [105] See a similar instance in Mach: Beiträge zur Analyse der Empfindungen, p. 36, a sparrow being the animal. My young children are afraid of their own pug-dog, if he enters their room after they are in bed and the lights are out. Compare this statement also: "The first question to a peasant seldom proves more than a flapper to rouse the torpid adjustments of his ears. The invariable answer of a Scottish peasant is, 'What's your wull?'--that of the English, a vacant stare. A second and even a third question may be required to elicit an answer." (R. Fowler; Some Observations on the Mental State of the Blind, and Deaf, and Dumb (Salisbury, 1843), p. 14.) [106] The reader will find a great deal about chronographic apparatus in J. Marey: La Méthode Graphique, pt. ii, chap. ii. One can make pretty fair measurements with no other instrument than a watch, by making a large number of reactions, each serving as a signal for the following one, and dividing the total time they take by their number. Dr. O. W. Holmes first suggested this method, which has been ingeniously elaborated and applied by Professor Jastrow. See 'Science' for September 10, 1886. [107] See, for a few modifications, Cattell, Mind, xi, 220 ff.