CEREBRAL LOCALIZATION 691 



other hand, beUeves that Amnion's horn does not form a part of the 

 olfactory area. 



The Center for Taste. — The psychic area for the sensations of taste 

 has not been definitely located as yet. As the taste buds are widely 

 scattered, their excitation involves the seventh and ninth cranial 

 nerves; in fact, Wilson^ states that a few of these receptors are also 

 situated in the mucous membrane of the larynx and epiglottis. The 

 latter seem to be innervated by the vagus nerve. In the medulla 

 these afferent fibers are intimately connected with the motor mechan- 

 ism concerned in mastication and deglutition, as well as with the 

 spinal nuclei. They terminate finally in the gyrus hippocampi near 

 the anterior end of the temporal lobe. In fishes these fibers may be 

 traced to the region of the hypothalamus. 



THE CENTER FOR SPEECH 



The Speech Circuit. — The psychic area for the associations required 

 in the production of intelligent sounds and speaking, should, of course, 

 not be confounded with that region of the cerebral cortex which has to 

 do with the innervation of the muscles of the larynx and functionally 

 allied structures and forms a part of the general motor area. In 

 fact, these motor points are under the direct control of the psychic 

 speech center. In the latter area the various revalent associations 

 from the visual, auditory and other centers are brought together and 

 are psychically adapted to speech. The speech center, therefore, is 

 the seat of those memories which are required for the execution of the 

 perfectly definite and coordinated movements necessary for speaking. 



Sounds are a common phenomenon in nature. We cannot, how- 

 ever, concern ourselves at this time with the reflex-like production of 

 noises, such as result in insects in consequence of the rubbing together 

 of the legs or mandibles. The first indications of true associated 

 sounds are present in amphibians and reptiles, but only in a rudimen- 

 tary manner, because the cerebral cortex of these animals is largely 

 concerned with olfaction. Such noises, however, as are produced by 

 means of resonating pouches, seem to contain at least a slight cortical 

 element. Somewhat higher in the scale of the Animal Kingdom this 

 psychic admixture becomes unmistakable. Its increasing conspicuous- 

 ness pursues a course parallel to the retrogression of the olfactory 

 apparatus and the development of the association areas pertaining to 

 other senses. Undoubtedly, this change is far advanced in the birds 

 and is almost complete in the monkeys and apes. In the mammals, 

 the production of sounds is universal and diversified, but the range of 

 these sounds is relatively limited. In other words, the sounds which 

 they produce are few in number, but are nevertheless made for very 

 specific purposes. In this connection, brief reference might be made 

 to certain seemingly authentic cases which suggest that it is possible 



1 Brain, xxviii, 1905, 339. 



