ANATOMY AND PHYSIOLOGY OF THE BRAIN. 409 



one-half of the body, but only of the muscles connected 

 with the two limbs (fore and hind), while those of the 

 trunk remain unaffected, as evinced in the normal con- 

 tinuance of respiration. 



THE BRAIN. 



The brain or encephalon is that part of the cerebro-spinal 

 axis, which is contained within the cranium, and may be 

 considered as simply an enlargement, consisting of numer- 

 ous ganglia at the anterior extremity of the spinal cord. 

 This part alone can hold direct intercourse with the mind ; 

 it only conveys sensations to the intellect, and gives rise to 

 acts of will. Forming thus the highest part of the system, 

 one rightly expects to find it attaining its greatest develop- 

 ment in those creatures which are most exalted in the ani- 

 mal scale. This is true in general terms, and yet requires 

 considerable qualification. It will be seen, by reference to 

 the table given below, that if we judge of the intelligence 

 only by the relative size of the brain, we must place the cat 

 highest, followed by the dog, rabbit, ram, goat, and donkey. 

 The horse will be degraded to a rank below all these, and 

 placed on a level with the most stupid of ruminants. It 

 would thus seem that nothing can be more liable to sources 

 of fallacy than any attempt to predicate the extent of the 

 intellectual endowments from the comparative development 

 of the brain. Not to enter at present into the discussion of 

 this subject, it may be stated that in no other animal does 

 the brain, as compared with the body, attain a bulk at all 

 proportionate to that of man that in no other class is its 

 development so great as in mammals ; and that in no inver- 

 tebrate animal is the brain so large as in the lowest speci- 

 mens of vertebrata. 



