FUNCTIONS OF CEREBRUM. 143 



It is unnecessary to enumerate the other portions of the 

 encephalon, of which the functions are doubtful, or entirely 

 unknown. 



Cerebrum. Observation has enabled physiologists to dis- 

 tinguish in the spinal cord and spinal nerves, and even in the 

 cranial nerves, the sensitive and motor portions; and we must 

 admit from the results of experiment in comparative ana- 

 tomy, that certain regions of the encephalon are endowed 

 with sensibility, while others are insensible; but we have not 

 yet been able to recognize in the encephalic mass the central 

 organs, which preside over sensation and over motion. No- 

 thing authorizes us to think that the insensible portions of 

 the brain do not take a part in the motor and sensatory 

 functions, and we are still less able to point out in the en- 

 cephalon the seat of intelligence. We see the intellectual 

 faculties develop themselves in the child, at the same time 

 with, and in proportion to, the development of the brain; 

 and we know that these faculties continue imperfect, or 

 changed, when the normal development of the organ is 

 arrested, and when it suffers from certain lesions; but these 

 facts, incontestable in principle, have no absolute applica- 

 tion. The brain may be wounded, and even a portion of it 

 may be destroyed, without any sensible change in the intel- 

 lectual faculties; a man of genius may have an ill-developed 

 brain, as Bichat, for example, whose cerebral lobes were not 

 of equal volume. On the other hand we see the intellect 

 clouded under the influence of alcohol, of certain poisonous 

 substances, or an attack of fever, and no trace is left in the 

 encephalon of the temporary disturbance ; sleep produces an 

 analogous effect; dreams are only a succession of false ideas, 

 a real delirium which ceases on awaking. And, indeed, in 

 the insane, science can in many cases prove nothing but their 

 misfortune, of which no part of the brain suggests in the 

 slightest degree the organic cause. Physiology, therefore, is 

 very reserved in regard to the cerebral functions, and most 

 of its theories concerning them are disputed and uncertain. 



The cerebral lobes do not seem to be essentially necessary 

 to the perception of sensitive impressions, general or special. 

 Thus, pathological observation has established the fact, that 



