Page:Popular Science Monthly Volume 27.djvu/84

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72
THE POPULAR SCIENCE MONTHLY.

many pathologists are disposed to regard it as substantially correct. It would seem just, then, to connect these central functions which are concerned in speech with the peculiarly developed region of the human brain that lies on the anterior and lower limit of the Sylvian fissure; Wundt adds that perhaps the Island of Reil should be joined to this territory.

We are now brought to consider directly the relation of portions of the brain to specific states of consciousness. I shall state the location of the senses as formerly made by Ferrier and by Munk, and will give a specimen experiment from each investigator. Sight is located by Ferrier in the angular gyrus (A, Fig. 1), by Munk in the occipital lobe (O, Fig. 1); hearing, by both, in the temporo-sphenoidal lobe (H, Fig. 1). Ferrier places smell and taste in the lower and inner aspect of the temporo-sphenoidal lobe (IT, Fig. 4). These centers are not distinguished by Munk. Ferrier names also a tactile center (H, Fig. 4). This he locates in what is known as the hippocampal region. If we separate the hemispheres from one another by cutting through the corpus callosum, we shall obtain a view of the median aspect of the hemispheres (see Fig. 4).

Attention has been called to the fact that Munk disagrees with all

PSM V27 D084 Right hemisphere of the human brain.jpg

Fig 4. — Median View of Right Hemisphere of Human Brain. (Ecker.) c c, Corpus callosum, connecting band between the hemispheres, longitudinally divided; w, lower and inner portion of temporo-sphenoidal lobe, center of smell, according to Ferrier; H, hippocampal fold, touch.

the authorities, except Schiff, in maintaining that a destruction of the motor centers destroys sensibility. Munk, therefore, does not indicate a special tactile center, but finds centers of feeling for head, neck, and back.

Ferrier's experiment with regard to vision was as follows: He chloroformed the animal, a monkey, and destroyed the angular gyrus