20 SPECIAL SENSES. 



six persons. 1 Aside from these observations, the repetition 

 of Weber's experiments has done little more than confirm 

 the original facts. 2 The table upon the next page, taken 

 from the article in the Cyclopaedia of Anatomy and Physi- 

 ology^ which we have already quoted, gives the results ob- 

 tained by "Weber and by Valentin. 3 



If we note the distribution of the tactile corpuscles in 

 connection with this table, it will be seen that the sense 

 of touch is most acute in those situations in which the cor- 

 puscles are most abundant. In the space of about one-fiftieth 

 of a square inch on the palmar surface of the third phalanx 

 of the index-finger, Meissner counted the greatest number of 

 corpuscles ; viz., one hundred and eight. 4 In this situation, 

 the tactile sensibility is more acute than in any other part of 

 the skin, the mean distance indicated by the sesthesiometer be- 

 ing 0-603 of a line. In the same space on the second phalanx, 

 forty corpuscles were counted, the sesthesiometer marking 

 1*558 line, this part ranking next in tactile sensibility after 

 the red surface of the lips. 



We can readily understand how the hard tactile corpus- 

 cles, embedded in the amorphous substance of the cutaneous 

 papillse, might increase the power of appreciation of delicate 

 impressions. 



As regards the general cutaneous surface in which no 

 tactile corpuscles have been demonstrated, it is not easy to 

 connect the variations in the tactile sensibility .with the ner- 

 vous distribution, as we know little or nothing of the com- 

 parative richness of the terminal nervous filaments in these 

 situations. 



1 VALENTIN, PTiysiologie des Menschen, Braunschweig, 1844, Bd. ii., S. 658. 



2 The above remark applies to a recent publication by Vierordt, on the 

 causes of the different development of the sense of locality of the skin (Archiv 

 fur die gesammte Physiologic, Bonn, 1870, Bd. ii., S. 297). In this article, it is 

 proposed to show that the tactile sensibility of the skin is acute hi proportion 

 to the mobility of the parts which it covers. 



3 CARPENTER, op. cit., vol. iv., part ii., p. 1169. 



4 See vol. iv., Nervous System, p. 40. 



