The Physician's Guide to Chemotherapy

Rotatory Reflexes", eight lectures. Discussions about colour vision occupy a large part of the first section. The trichromatic theory is shown to be inadequate because yellow and black are differentiated by retinal receptors and the differentiation is not the result of "higher" integration. Hering's theory is revived, but modified to suit subsequent physiological thought. The author postulates a dominator (grey) mechanism for the discrimination of brightness from white to black, and two pairs of mutually exclusive modulators (red-green, yellow-blue) for colour reception. Hartridge's or other polychromatic theories are not mentioned. The author shows that visual acuity depends on our faculty to distinguish quantitative differences between light stimuli (light sense); and the "form sense" as a separate entity does not exist. The "sense of contrast" and "sense of position of objects" are also fictitious. "The Perception of Spatial Relationships" is the most interesting section. The unconscious statistical analysis of visual stimuli replaces the theory of retinal projection and local sign. The Vieth-Miiller horopter is given a place of honour, and an impressive series of horopters by Luneburg, Hildebrand and Hartridge amplify the geometry of visual space. A chapter on perspective brings an interlude on modern art. Experiments of Ames are described, but anisiekonia is considered to be a relatively uncommon cause of clinical symptoms. The theories of Gestalt psychology influence many conclusions.