. Anatomy, descriptive and applied. Anatomy. 860 THE NERVE tiYHTEM they were inimical or indifferent or beneficial to its individual ends. The sensor periphery, in consequence of the demands of evolution, underwent specialization in the development of olfactory and gustatory organs for testing the quality of the food and of the surrounding medium; optic organs for perceiving rays of light; auditory organs for the appreciation of certain oscillations of the surrounding medium; while others, strictly tactile in nature, underwent elaboration as such in the development of sensitive antenna or tent
. Anatomy, descriptive and applied. Anatomy. 860 THE NERVE tiYHTEM they were inimical or indifferent or beneficial to its individual ends. The sensor periphery, in consequence of the demands of evolution, underwent specialization in the development of olfactory and gustatory organs for testing the quality of the food and of the surrounding medium; optic organs for perceiving rays of light; auditory organs for the appreciation of certain oscillations of the surrounding medium; while others, strictly tactile in nature, underwent elaboration as such in the development of sensitive antenna or tentacles. Motor contrivances, useful in the quest for food or in encounters with the enemy, were developed in the way of powerful jaws and masticatory muscles. In brief, a remarkable specialization and differentiation of structure attended the development of the head end, and with it the central organ of control kept pace. In the human species we find certain of these structural characteristics in a highly developed condition, while others have dwindled or disappeared in the course of evo- lution. Thus, in the myxinoid fishes and the lamprey the cere- bral hemispheres themselves are mere appendages of the olfactory lobes; the sense of smell was prob- ably the most important in lower animals. In the brain of man conditions are reversed and the olfactory system is seen to have dwindled to an extreme degree as compared with the immense size of the cerebrum; this in conformity with the relatively slight use made of the smell sense in the mental life of man. Other organs of special sense, however, became augmented, and these, together with the nerve mechanisms controlling the vital functions (respiration, circulation), required a more and more elaborate central nerve organ for the harmonious interaction of the several elements. This central organ or brain developed, in bulk and complexity, hand in hand with the increase of the intellectual faculties. Man's most manifest distinction fro
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectanatomy, bookyear1913
