DEKMATOGLYPHICS IN PRIMATES 163 



structure in which only rings and " warts" occur. Naturally 

 there can be no whorl or any type of pattern at this level of 

 epidermal specialization. Even in forms presenting actual 

 ridge formation in areas of limited extent the potential ex- 

 pressions of patterns may be restricted by the lack of formed 

 ridges. In the sole of Aotus (figs. 138-149), for example, the 

 hypothenar region is only incompletely ridged and hence 

 incapable of giving full expression to patterns. Ridge ir- 

 regularities such as those shown in figure 138 are indicative 

 of contours which might have been associated with a well 

 formed pattern had not the extent of ridge formation been 

 so limited. In contrast to this, Galago (figs. 29-32) shows 

 completed "primitive" patterns, whorls and whorl-like de- 

 signs, on a volar surface which is elsewhere lacking in ridge 

 formation. Comparing Galago and Tarsius, Galago presents 

 a relatively more extensive region in which ridges are lacking, 

 and the ridged areas bear whorls and whorl-like patterns, in 

 contrast to the extreme simplicity of ridge arrangement in 

 Tarsius. Which of these two prosimians is more primitive 

 with respect to dermatoglyphics I If whorls be accepted as the 

 index, Galago has the claim, but it might be urged that the 

 open fields of Tarsius are the primitive configuration, inas- 

 much as the reading of descriptive affinities among configura- 

 tion types without regard to pad expression is as convincing 

 when begun at one extreme as at the other. Considering as we 

 do that the whorl is a primitive type, Galago is viewed as 

 being far more primitive in its dermatoglyphics than Tarsius. 

 In support of the validity of the chosen point of reference it 

 should be recognized that if there be adopted any other 

 sequence of patterns from the more primitive to the more 

 specialized than that beginning with the whorl, an irreconcila- 

 ble conflict with other standards of taxonomic grouping would 

 result. The gibbon, great apes and man would then be as- 

 signed to a group more primitive than the monkeys and most 

 prosimians. 



The evaluations of pattern intensity which have been fol- 

 lowed in our analyses may be regarded as measures of vary- 



