DEEMATOGLYPHICS IN PRIMATES 175 



represent a record of the pad characteristics at the time of 

 ridge formation. In man that period is at the close of the 

 first trimester of gestation and the beginning of the second. 

 Whether other primates would undergo the critical phases of 

 ridge differentiation and pad development at a relatively 

 equivalent period can only be conjectured. It may be repeated 

 that the comparison of dermatoglyphics among genera is in- 

 trinsically a comparison of fetal volar reliefs, reliefs which 

 are variably retained or modified in the adult. 



GENERIC AND GROUP COMPARISONS 



Most of the following comparisons are confined to genera 

 represented by reasonably adequate numbers of specimens. 

 The best introduction is provided by Old World monkeys, the 

 only group in which the several genera studied are fairly 

 uniform in their characteristics. These characteristics indi- 

 cate generalization, or primitiveness. Prosimians, New World 

 monkeys and great apes are. not considered collectively as 

 groups because there is no such consistency among their 

 genera. 



Old World monkeys. This group comprises the most pro- 

 nounced walkers. It is therefore perhaps not unexpected that 

 the prevailing characteristics of dermatoglyphics are of the 

 type associated with a high development of pads. Ridges are 

 continuously formed except that small areas of imperfect 

 ridge structure are occasionally noted in some Colobinae. De- 

 partures from the morphologic plan of configurational areas 

 are at a minimum, the most important being the frequent 

 merger of Th and I. Total pattern intensity is high both in 

 palm and sole. There is but little difference between hand 

 and foot in the^r total intensities, and the existing difference 

 is in the same direction as in non-human primates generally, 

 the higher value being in the palm. Pattern intensities of the 

 hypothenar and thenar groups of configurational fields, both in 

 palm and sole, are substantially equal, as are the groups in the 

 palm compared with the regionally corresponding groups in 

 the sole. The relative pattern intensities of the three disto- 



