70 THE SENSE OF TOUCH IN ANIMALS 



than the Gorilla orOrang, but more so than the Gibbon, The 

 apical pads show simple elhpses, and are thus less human than 

 those of the Gorilla, the remaining digits have arches and 

 loops. The palmar and plantar surfaces are as simple as those 

 of the Gibbon, the ridges being longitudinal and oblique. 



The features by which the Anthropoid Apes stand out in 

 contrast to all the Primates below them are : (1) marked simpli- 

 city of palmar and plantar patterns ; (2) higher development 

 of apical pads in the Orang and Gorilla ; the former change 

 is common to the whole group, the latter to only two out of 

 the four. The patterns of the Gibbon's hand and foot point 

 to these being simpler in organisation than those of the other 

 Anthropoids, and that its hand is more functionally important 

 than its foot. 



Man. — The patterns on the human hand and foot present 

 marked differences from the Anthropoid Apes. It may be 

 well to notice a statement made by Dr. Hepburn* on this 

 point. He says : "I find among those which have come mider 

 my notice, that although the monkey patterns are undoubtedly 

 simpler and of less varied design than the patterns found in 

 man, there is, nevertheless, a considerable amount of variety 

 among them." Also " In comparing the lower monkey patterns 

 with those of man, the most noteworthy feature is the great 

 simphcity of the former." 



These statements are not borne out by the present study, 

 and are misleading in one important respect. They are only 

 correct when apphed to the patterns on the apical pads of the 

 hand and foot. The striking fact as to other parts of the hand 

 and foot is that simplicity of pattern is the characteristic in 

 the Anthropoid Apes and man. It is instructive to see the 

 change of function from palm and sole to digit written in these 

 legible characters on the skin of monkeys, apes, and man, also 

 the general arrangement of ridges on the palm and sole of the 

 anthropoids, by which the longitudinal grouping of the ridges 

 comes into play, subserving the prehension of spherical objects 



* The Papillary Ridges on tlie Hands and Feet of Monkeys and Man, 

 Trans. Royal Dublin Society, vol. v. 



