Chapter XX

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[94] We never, so far as I know, get the converse illusion at a railroad station and believe the other train to move when it is still.

[95] Helmholtz: Physiol. Optik, 365.

[96] Cf. Berkeley's Theory of Vision, §§ 67-79; Helmholtz: Physiologische Optik, pp. 630-1; Lechalas in Revue Philosophique, xxvi. 49.

[97] Physiol. Optik, p. 602.

[98] It seems likely that the strains in the _recti_ muscles have something to do with the vacillating judgment in these atropin cases. The internal recti contract whenever we accommodate. They squint and produce double vision when the innervation for accommodation is excessive. To see singly, when straining the atropinized accommodation, the contraction of our internal _recti_ must be neutralized by a correspondingly excessive contraction of the external _recti_. But this is a sign of the object's recession, etc.

[99] American Journal of Psychology, i. 101 ff.

[100] Romanes, Mental Evolution in Animals, p. 324.

[101] M. Lazarus: Das Leben d. Seele, ii (1857), p. 32. In the ordinary hearing of speech half the words we seem to hear are supplied out of our own head. A language with which we are perfectly familiar is understood, even when spoken in low tones and far off. An unfamiliar language is unintelligible under these conditions. If we do not get a very good seat at a foreign theatre, we fail to follow the dialogue; and what gives trouble to most of us when abroad is not only that the natives speak so fast, but that they speak so indistinctly and so low. The verbal objects for interpreting the sounds by are not alert and ready made in our minds, as they are in our familiar mother-tongue, and do not start up at so faint a cue.

[102] G. H. Meyer, Untersuchungen, etc., pp. 242-8.

[103] Helmholtz, P. O. 438. The question will soon come before us again in the chapter on the Perception of Space.

[104] C. F. Taylor, Sensation and Pain, p. 37 (N. Y., 1882).

[105] Examen Critique de la Loi Psychophysique (1883), p. 61.

[106] Compare A. W Volkmann's essay 'Ueber Ursprüngliches und Erworbenes in den Raumanschauungen,' on p. 139 of his Untersuchungen im Gebiete der Optik; and