68 THE SENSE OF TOUCH IN ANIMALS 



developed more fully, tlie proximal phalanges showing bilateral 

 whorls on two, and single whorls on two other digits, instead 

 of arches. The hand is also more complex than the foot. 



Baboons. — The two Baboons present short-stunted digits, 

 and thick fleshy hand and foot, especially Papio porcarius. 

 They are notable for being the earhest to show loops on the 

 terminal phalanges. They have well-defined whorls on palm 

 and sole, but little variation on the digits, except for loops of 

 ridges on the digits of the foot of Papio yorcarius. The ridges 

 are more marked on the most highly developed parts of the 

 hand and foot than elsewhere. 



The Black Ape and Mangabey do not present any advance 

 on the Baboons as to the palm and sole, but marked arches, 

 loops, and whorls on the digits of both hand and foot. 



Macacus. — Three Macacai — silenus, nemistrinus and cynomo- 

 logus — show a few small differences between one another, and 

 between the hand and foot. M. silenus and nemistrinus have 

 wide elhpses on the apical pads of the hand, indicating a higher 

 degree of development than that of M. cynomologus. The 

 hand in each of these three species is more complex than the 

 foot. Of all three the hand of M. cynomologus, with marked 

 palmar and digital whorls and loops is the most highly developed, 

 and the foot of this species with its roughened and bare proximal 

 and middle phalanges, is the least developed. M. nemistrinus 

 has marked arches on the digits of both hand and foot, M. 

 silenus both better marked ovate whorls on the apical pads, 

 and more loops and rudimentary arches than the other two, 

 being thus distinguished by a more uniform advance in com- 

 plexity of pattern. 



The Patas Monkey has well- developed patterns on the apical 

 pads of hand and foot, arches and loops on the digits. On the 

 fore part of the palm and sole there are whorls and wide loops, 

 the proximal part being very simple, and the ridges here are all 

 longitudinal or oblique. 



From the highest of the monkeys to the Anthropoid Apes 

 a considerable change is to be found ; one each of the four 

 genera has been examined. 



