ABSTRACT
This chapter examines the specific differentiation of the perceptual processes of the Primates. Unfortunately this is a field which has been studied very little as yet, and available knowledge is limited almost entirely to the functions of vision and smell. Experimental data relating to the subject are scanty, and refer almost entirely to the apes and catarrhine monkeys. Much is known about the structural characters of the ocular apparatus of almost all Primates, and the information allows fairly safe inferences about function. One of the striking characteristics of the primate brain, as Elliot Smith has pointed out, is the reduction in the part of the cerebral hemisphere concerned with smell, and the corresponding increase in the cortical representation of visual functions. Like those of most sub-primate monodelphian mammals, the eyes of the members of the sub-order, even of the short-snouted Galagos, are set more to the sides than to the front of the head, the visual fields overlapping very little.
