OUR BRAINS. 



59 



illustrated. As a matter of course, in animals the faculties for 

 search of prey, for acuteness to recognize quickly the approach of 

 enemies, and to guide them surely and swiftly out of danger, are 

 of the highest importance. The centres presiding over these 

 faculties constitute the great mass of the brain. In a diagram of 

 the brain of a cod-fish was shown their predominance over the 

 cerebrum, the organ of the reasoning faculty. In men of inferior 

 type the skull in shape approaches more nearly to the skull of 

 lower animals than in highly intellectual races. It is not, however, 

 that the cranio-spinal axis is developed only to a small degree in 

 man, but that the vast predominance of the cerebrum throws it 

 into the shade. The cerebellum used to be looked upon as the seat 

 of the passions — anger, love, hate, &c. ; but physiological research 

 has proved this wrong. This centre presides over the co-ordination 

 of muscular action, or, in other words, the production of actions 

 in accordance with one another, and the requirements of the motion 

 to be made. 



The difference between the human brain and that of the highest 

 brute is seen at a glance. In man we have developed to its greatest 

 extent the cerebrum. In man the cerebrum overlaps all the rest, 

 and forms the great bulk of the contents of the skull. It consists 

 of two lateral halves, known as the hemispheres, and a connecting 

 band, the corpus callosum. The grey matter lies on the surface, 

 forming a coating over the white. The surface is not uniform, as 

 in many lower animals — the rabbit for instance, but everywhere 

 covered with convolutions. The depth and number of these deter- 

 mines the amount of grey matter. The convolutions are most 

 marked in the prime of life, and in persons of great intellectual 

 energy. In old persons and children they are comparatively flat. 

 They are not constant, but offer every variety of configuration. 



That the brain is the organ of the mind, the lecturer thought no 

 one for a moment would (juestion. If it were not so, what would 

 be tlie use of this large organ, so largely connected witli the rest 

 of the body ? In animals, as the various attributes that are com- 

 monly supposed to belong to the mind increase, the brain increases. 

 If the nerve supplying any particular part be divided, the connec- 

 tion between the mind and that part ceases. Therefore lie held the 

 brain to be the organ of the mind. Reason and faculties, such as 

 feeling and the various emotions, are the attributes of that invisible 

 essence the mind. A large brain, like a large man, is capable of 



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