Page:Popular Science Monthly Volume 27.djvu/86

74, he did not strike against any object, and if things were put in his way he uniformly avoided them. There was, however, a striking difference. He regarded very coldly those men whom he used to greet most affectionately. He was indifferent to the dogs he always played with before. However hungry and thirsty he was, he did not go to the corner of the room where his food was, as formerly; and, if food and water were placed directly in his path, he would go round and round them without noticing them at all. The sight of the whip, which used to drive him into the corner, did not now produce the slightest effect. He used to raise his paw when your hand was moved before his eyes; now he will not lift it, however much the hand is moved."

From these and similar facts, Munk draws a conclusion which, to say the least, seems a trifle broader than the premises. He says: "There can be no doubt about the meaning of these observations. By the extirpation of this portion of the brain, the dog has become soul-blind. He has lost the sight-perceptions which he once possessed; his recollection-images of things seen before are gone, so that he can not recognize what he sees—still he sees; sensations of sight come to his consciousness, so that he receives a knowledge of the existence, form, and position of external objects, but he does not know what these mean—this knowledge must be learned anew. The dog has been set back to his earliest years, to the time when he first opened his eyes; he must learn to see."

As removal of this part of the occipital lobe causes soul-blindness, so a removal of a portion of the temporo-sphenoidal lobe causes soul-deafness.

Until lately the defenders of localization seemed to be justified in believing that something had been established as to a motor area of the brain; they might well feel, also, that a beginning had been made toward connecting certain parts of the cortex with specific sensations and might hope that further experiment would remove, in considerable degree, the present disagreements. The doctrine of localization, both as a whole and in detail, has, however, received a severe blow at the hands of Professor Goltz, of Strasburg. In 1876 this distinguished experimenter began the publication of a series of papers in "Pflüger's Archiv fur die gesammte Physiologic" In September, 1881, this series was finished and published by itself. Professor Goltz fearlessly declares that he has overthrown all the conclusions about division of the brain into motor and sensory areas, and brought back our knowledge of brain-function to the old view of Flourens, viz., that the cerebrum is one organ, having one function throughout. Professor Goltz's experiments were confined entirely to dogs, and their chief significance is due to the fact that he was able to keep the animal alive after removal of larger masses of the cerebrum than any other experimenter. These experiments seem to have been abundant and thorough. As a