NERVOUS SYSTEM 235 



2. The grey matter contains : 



Cephalin, lecithin and cholesterin . i'95o per cent. 

 Cerebroside, cerebrinoid and myelin 0*424 ,, 

 Lecithin, cephalin and myelin . 0*780 

 Inosit . . . . . . O'i93 



Lactic acid . . . . . O'iO2 



Alkaloids 



Sulphates (in neuroplastin) . . O'o6 



Sulphates (in extract) 



Phosphates ..... 0*017 



Potassium ..... 0*017 ,, 



Sodium ...... 0*092 



Water extract .... 0*500 



Water 85*270 



Neuroplastin ..... 7 '608 

 A complete human brain yields 18-20 gms. of ash with 48 

 per cent, of phosphoric acid (i free, ^ in combination). The 

 ash of the fresh white matter amounts to about 1*7 per cent, 

 of the grey about I per cent. ; the same proportions have been 

 found in the brains of oxen. 



As already mentioned in the section upon anatomy, the first 

 feature in which man appears superior to all the other animals 

 is the preponderance of the cerebral hemispheres over the mid- 

 brain, and the second is the greater wealth of fibres descending 

 from the hemispheres in the peduncles of the cerebrum. The 

 mid-brain (corpus striatum, optic thalamus and corpora quadri- 

 gemina) contains, both in man and beast, the centres for co- 

 ordination of movement. 



The cerebral peduncles and the pons convey the motor- 

 fibres to the anterior horn-cells, and the sensory-fibres from the 

 periphery through the spinal cord to the brain. ' Each lobe 

 of the cerebellum exercises not only a direct but probably a 

 bilateral control over all voluntary muscles, by means of which 

 movements are co-ordinated and adjusted so that the equilibrium 

 of the body may be maintained. Associated movements and 

 sensations are brought about by the central organs. 1 



The basal ganglia of the brain are the organs of mere 

 physical control from which are given off the impulses demand- 



1 Munk-Schultz, loc. cit., pp. 477-93. 



