DEEMATOGLYPHICS IN PRIMATES 167 



be lowered in one group more than in the other, and in com- 

 paring the corresponding regions of different members their 

 unlikenesses in pattern intensity would reflect membral 

 specialization. 



The second mode of regional grouping separates three sets 

 of configurational fields arranged in disto-proximal sequence : 

 a distal set (II and IV), an intermediate set (I and H d ) and 

 a proximal set (Th and H p ). In the theoretically most primitive 

 state, the intensities of these three groups would be equal, 

 but our observations indicate that the presumably most primi- 

 tive condition actually manifested is one in which the intensity 

 of the distal set is greater than that of the intermediate, 

 which in turn is greater than the proximal set. The expression 

 of such a gradient in pattern intensities is based upon progres- 

 sive specialization in a disto-proximal direction, just as in 

 the thenar and hypothenar groups specializations on one or 

 the other side of the anatomical axis are indicated by lowered 

 intensity. 



The third interdigital configurational field, not included 

 in either of the groupings just described, needs no special 

 discussion as to the criteria of primitiveness, inasmuch as it 

 is a single area ; specialization of the region, as elsewhere, is 

 associated with lowered pattern intensity. 



(4) As for comparisons of total pattern intensities in palm 

 and sole, it is assumed that the ultimate primitive condition 

 would be equality of these members in having the maximum 

 possible intensities. Actually, equality is not observed, ex- 

 cept in Pan, where it is the result of equal specialization 

 indicated in correspondingly lowered intensities. It is pos- 

 sible that some factor associated with cephalocaudal gradients 

 is responsible for the characteristically greater pattern in- 

 tensity of the palm, but it is assumed that unusually wide 

 differences are associated with unlike membral specialization. 



(5) Since bilateral asymmetry is a widespread phenomenon 

 and the agencies of its different expressions are not identifi- 

 able, it would be unwise to select a particular degree of asym- 

 metry as a standard of primitiveness. However, the position 



