326 STUDIES, SCIENTIFIC AND SOCIAL chap. 



render them effective organs are most exposed to injury, 

 as in the pahii of the hand and the hollow of the foot, and 

 especially on the under side of the arm just above the 

 wrist. The parts of the body which are less sensitive are 

 those where there are masses of muscle, the puncture of 

 which would not cause any serious injury. It will thus be 

 seen that sensitiveness to pain from external agencies is 

 not at all proportioned to the frequency of contacts, but to 

 the vital imjDortance of the parts to be protected ; and it 

 is, therefore, such as could not possibly have been pro- 

 duced by inherited use, but must have been developed 

 solely by the preservation of useful variations ; and as it 

 is essentially a life-preserving faculty this would inevitably 

 have been effected. 



It seems most probable that the faculty of tactual dis- 

 crimination of adjacent points is partly an incidental 

 result of the distribution of nerve-endings required by 

 skin-sensatien as a preservative faculty, and partly the 

 result of use and attention in the individual. All the 

 facts adduced by Mr. Spencer are in accordance with this 

 view, while none of them in the slightest degree necessitate 

 inheritance of individual experiences to account for them. 

 To show any probability of such inheritance it must be 

 proved that this tactual discriminativeness is a special 

 faculty, due to a different set of nerves from the known 

 nerves of sensation, which, I believe, has never even been 

 suggested. But if it is due to the same nerves, then to 

 separate this small and comparatively unimportant func- 

 tion of skin-sensation from the great and vitally important 

 functions the faculty subserves, and to found upon this 

 artificially isolated and unimportant fragment an argument 

 against the adequacy of natural selection, is not only 

 quite inconclusive, but, as an argument, is altogether null 

 and void. 



Argument from Rudimentary Eyes. 



The next point discussed by Mr. Spencer is the mode in 

 which the eyes of the Proteus of the Carniola caverns have 

 been reduced to a rudimentary condition ; his argument 

 being, that, unless the reduction in size by disuse was 



