DIFFERENCES OF SENSIBILITY. 335 



to exist ill all the higher animals, though in a feebler degree 

 than in man. Even among men the difl'erence of suscepti- 

 bility is very remarkable. It is much less in savages than 

 in highly-civilised men, as it seems also to be less in wild 

 animals than in domesticated, especially petted, animals ; 

 less in men leading an active out-of-door life than in those 

 leading a sedentary intellectual life ; less in women than in 

 men ; less in persons of lymphatic than in persons of 

 nervous temperaments. To one man the scratch which is a 

 trifle scarcely noticed, is to another an obtrusive pain ; the 

 one will not even tie his handkerchief over the wound, so 

 little does it press upon his sensibility ; the other is pale, 

 and must have the wound dressed. 



It is because men habitually confound Sensibility with 

 Pain — the general with the particidar — that so many disputes 

 continue respecting the sensibility of certain parts of the 

 nervous mechanism ; for instance, the disputes as to whether 

 the Sjrmpathetic system is also a Sensitive system. But no 

 correct understanding of the nervous system can be arrived 

 at until more rigorous language is adopted, and we leani to 

 designate all nerve-actions by the one general property of 

 Sensibility, and to discriminate between this general property 

 and its special manifestations. Pain is, I believe, a special 

 form of this general Sensibility ; and although anatomy has not 

 yet detected the special Centre wherein stimuli are trans- 

 formed into sensations of pain, there can be Little doubt that 

 such a Centre exists, and none at all, in my mind, that the 

 lower animals have it not ; and tliis conviction keeps me 

 perfectly calm in performing experiments on marine animals : 



