182 CHARLES MIDLO AND HAROLD CUMMINS 



the palm proper the zone of the first metacarpal and the as- 

 sociated first interdigital configurational area. The intensity 

 of patterning in the palm and sole is the lowest in all the 

 simians, and there is pronounced modification of the funda- 

 mental plan of dermatoglyphics. There is a marked difference 

 of pattern intensities of palm and sole (index 143, which is 

 close to that of several New World monkeys). The thenar 

 and hypothenar groups (see fig. 600) show reversed tendencies 

 in the intensities of pattern of palm and sole, the palm having 

 a higher pattern intensity in the hypothenar group and the 

 sole a higher intensity in the thenar group. The pattern in- 

 tensities of the three transverse groups of configurational 

 fields present, as compared to Old World monkeys, a reversal 

 of the relative intensities of distal and proximal groups both 

 in palm and sole. While the total asymmetry in gibbon is 

 much higher than in any of the monkeys, the relationships of 

 members of the two sides, as indicated in the asymmetry index, 

 conform to the generalizations set down for the New World 

 monkeys. The magnitude of bilateral asymmetry is much 

 higher than in any monkey, though the proportionate asym- 

 metry in palm and sole is like that of most monkeys, and is 

 much lower than is the case in the great apes and man. 



Great apes and man. Sharp differences in locomotor habits 

 and modes of existence occur among these four genera. All 

 the great apes are partly arboreal, and man is at least 

 potentially so. ' ' The orang-utan spends practically his entire 

 life in the trees, the chimpanzee, though an expert in trees, 

 spends a good deal of time on the ground, and the gorilla is by 

 far the least arboreal great ape, the enormous adult males 

 ascending trees but rarely." (Schultz, personal communi- 

 cation.) Taking into account all dermatoglyphic criteria, 

 Pongo, the most arboreal, and Homo, the most terrestrial 

 form, may be assigned respectively to the lower and upper 

 extremes of specialization, Pan and Gorilla being intermediate. 

 With regard to adherence to the basic plan of dermatoglyphics 

 alone, Pongo and Homo are unquestionably the least special- 

 ized, while Gorilla and Pan are the most highly specialized 



