100 THE GENERAL ANATOMY OF THE TARSII [SECT. A 



more completely covered by such pads than is the case in the 

 Lemur. Five apical pads are to be seen in hand and foot alike. 

 Of the interdigital pads, all four are observed on the hand, but 

 only two on the plantar surface of the foot, where the second has 

 joined the third, and the fourth is merged in the " antithenar" pad. 

 On the vola (palm) two proximal pads appear, and that on the 

 thenar side is continuous with the first interdigital pad. On 

 the plantar surface the two proximal pads have united towards the 

 heel and thus form a V-shaped mass. On the whole, the primitive 

 distribution of the pads is still clear. Between the pads, small 

 nodules are present, though these are much less numerous than in 

 the Lemur. Papillary ridges are found on the pads and on the 

 nodules, and Schlaginhaufen considers that the extent of surface 

 thus marked by ridges is greater relatively in Tarsius than in 



Fig. 55. Tarsius spectrum. Scheme of the hair-tracts on the upper limb. 

 (From Schwalbe.) 



Lemurs. If this be so, the higher position is to be accorded to 

 Tarsius. 



The apical pads are marked in a fashion closely resembling the 

 pattern already described for the Lemur (cf. supra p. 71). But 

 the sinus primarii (on the strictly ventral aspects of these pads) 

 have been subjected to a curious torsion in their relation to 

 the terminal loops marking the extreme tips and the dorsal aspects 

 (Schlaginhaufen, op. cit. fig. 102 c). On the palmar surface the 

 proximal and interdigital pads (Fig. 56) bear slightly-curved 

 ridges with two " tri-radii " at most. The phalangeal surfaces are 

 similar in marking to those of the Lemur. Specimens of Tarsius 

 at Cambridge shew a more extensive area thus distinguished 

 (on the phalanges) than the example figured by Schlaginhaufen, 

 but the second digit is (in both cases) less marked than the 

 others. 



