720 A TEXTBOOK OF PHYSIOLOGY 



The palaeo-encephalon was normal, as well as the rest of the brain, 

 except for the lack of fibres arising from the neo-encophalon, such 

 as the fibres to the red nucleus, to the pons, and to the spinal cord. 

 Till the day of its death the child scarcely altered its behaviour, 

 and presented a marked contrast to a brainless dog. It had never 

 made any attempt to raise itself up, or to take anything in its hands 

 and hold it. The only movements were those of the face, which 

 sometimes took on an expression of pain. The lips and tongue were 

 used in sucking and taking food from a spoon. After two years it 

 uttered a dull cry, which could be soothed by pressing its head. Urine 

 and fseces were passed in any position, and it did not display any 

 discomfort at being wet. The child appears not to have shown 

 periods of wakefulness and sleep, but to have always slept. The 

 light reflex was present, the eyes being shut tightly when light was 

 thrown on them. It was impossible to elicit any sign of psychic 

 reaction, to train or teach the child in any way. Without the mother's 

 help, the child would certainly have perished. New-born babies 

 behave in much the same way, because in them the connection between 

 the new brain and the old brain is not yet developed. The same is 

 true for all mammals. These, unlike fish, amphibia, and reptiles, 

 are almost wholly paralyzed without the new brain. The importance 

 of the new brain gradually increases as we ascend the scale, until in 

 man it becomes paramount. 



There has also been reported the case of a man from whom it was 

 found post mortem that a cerebral hemisphere had been missing. 

 Although hemiplegia and hemianaesthesia were present, the intelligence 

 of this individual was normal. So in many cases of injury in man 

 large masses of brain tissue have been lost which, while involving loss 

 of sensation or of movement, have apparently scarcely affected the 

 intelligence. 



From such evidence, then, it is clear that brainless animals are 

 incapable of perceiving certain stimuli, that they possess no associative 

 memory, are incapable of psychic processes, and are not able to initiate 

 any of the movements which normally result from such processes. 

 The functions of the great brain may therefore be grouped as (1) The 

 reception of impulses (a receiving sensory mechanism) ; (2) the storing 

 of the effects of such impulses, and the association of present with 

 stored impressions (a storing and associating mechanism), resulting 

 in the highest processes of the brain discrimination, inhibition of 

 emotion, judgment; (3) the production of actions as the result of 

 these (a motor or discharging mechanism). 



It has been found that the receptor and effector mechanisms of 

 the cortex cerebri are more or less localized in special parts. Such 

 localization has been effected by five methods: (1) The effects of 

 removal of parts of the cortex; (2) the effects of stimulation of parts 

 of the cortex; (3) by clinical observations in cases of brain disease, 

 followed by an investigation of the central nervous system after 

 death ; (4) by a histological examination of the cerebral cortex ; (5) by 

 a, study of the nerve tracts during their development. v 



