DERMATOGLYPHICS IN PRIMATES 19 



with terms which may be fittingly assigned to primates 

 generally. 



Included in the basic plan here adopted are five smaller 

 pads which had not been completely systematized heretofore : 

 two (IP on the radial side of II, and 1V U on the ulnar side of 

 IV; IP and IV f corresponding in the sole) are located in as- 

 sociation with the marginal set (Nycticebus, Aotus, fetal 

 man) ; and three (respectively 2 P , 3 P and 4 P ) lie in the central 

 area of the palm (zentrale Ballen, Schlaginhaufen) proximal 

 to the three interdigital pads. 



In summary, it may be stated that the pads fall naturally 

 into two groupings, hereafter termed border pads and central 

 pads. Distributed around the margin, the border pads include 

 H d , H p , Th, I, IP(IP), II, III, IV, and IV u (IV f ). The central 

 pads comprise 2 P , 3 P and 4 P . If the calcar elevation (C) be 

 considered a true pad it would be assigned to the series of 

 border pads, and perhaps specifically identified as an element 

 of the hypothenar. 



It is not intended to present a fully detailed description of 

 the volar pads. The reader is referred to Klaatsch, Whipple, 

 Kidd and Schlaginhaufen for more extended descriptions of 

 their modifications in various genera. Our concern with pads 

 is limited to their participation in a common plan of pads 

 and configurational fields and to their influence on the pro- 

 duction of specific ridge configurations. At this point atten- 

 tion may be called to the fact that forms which possess the 

 most prominent volar pads (e.g., Old World monkeys) are 

 characterized by the high degree of development and fre- 

 quency of patterns. Conversely a form which presents little 

 or no indication of well-marked pads (for example, Hylobates) 

 shows a marked reduction in frequency and complexity of 

 patterns. It does not follow that such inverse relationships 

 of pads and patterns are inevitable, for in great apes and in 

 man patterns of much complexity may occur in the absence 

 of prominent pads. This lack of complete correspondence 

 between pads and patterns in adult primates is explained 

 below on a developmental basis. The ultimate correlation 



