KNOWLEDGE, 



[January 1, 1901. 



well be left for the professors of palmistry to explain 

 as best they can ! 



As regards the structure of the palmar ridges, an 

 examination of the reader's own hand with a lens will 

 easily show that these consist of a series of very minute 

 cone-like elevations, placed close together, and on the 

 summits of which are situated the apertures of the 

 sudoriferous or sweat glands. 



If a section of the skin 



.Ir 

 ..Cl 



1 



Fig. 1. — Right Palmar Imprint of a Macai.|ue Mopkey {Macaciis 

 ct/nomolffus); a, b, c, interdigital eminences; d, raciial eminence; 

 e, ulnar eminence. 



be examined under a microscope, it will also be evident 

 that within these papillae are certain organs of touc'i 

 known as the tactile bodies. Between the papillary 

 ridges, as we luay now term them, are situated the 

 equally narrow grooves, which contain neither sweat- 

 glands nor tactile bodies. 



Looking cai-efully at Fig. 1, and, if necessary, employ- 

 ing the aid of a lens, it will be seen that the ai'rangement 

 of the ridges and grooves, instead of being unifoi-m over 

 the entire palm, takes the shape of a series of definite 

 patterns in certain areas, between which a more or less 

 regular linear arrangement obtains. On the ball of each 

 finger and the thumb, for example, it will be noticed that 

 the ridges assume what may be termed a concentric 

 pattern, in which the central ridges run longitudinally. 

 Again, on the three eminences situated on the palm 

 opposite the clefts between the four fingers, they take the 

 form of concentric whorls {a, h, c). A similar radial 

 eminence (d) with a whorl-like pattern is situated opporsite 

 the cleft between the thumb and the fore-finger; while yet 

 another whorl-bearing elevation (e), which may be termed 

 the ulnar eminence, has its position at the basal angle 

 of the palm opposite the little finger. Minor eminences, 

 with much less distinct patterns, also occur on the 

 palmar surfaces of the two basal joints of the fingers. 

 Between these various pattern-bearing eminences, as is 

 especially well shown on the fingers, the ridges and 

 grooves tend to arrange themselves either in transverse 

 lines, or (in the words of Dr. Hepburn) with siich slight 

 modification of this direction as would place them 

 parallel to the long axis of any cylindrical object which 

 might be grasped by the foot. It may be added that 

 although in the human hand the patterns found on the 

 balls of the fingers are frequently more complex than 

 those in the monkey's hand, yet the converse of this is 



true with regard to the eminences on the palm itself, 

 the ulnar whorl being generally quite obsolete in man. 



In ordinary five-fingered monkeys, whether they kail 

 from the Old" World or from the New, the foregoing type 

 of eminences is veiy constant. This is well exemplified 

 by the impression of the hand of one of the South 

 American Capuchin monkeys (Fig. 2). Here, however, 





'k ^h f 



Fig. 2.— Eij;l)t Talmar Impres- Fig. 3. — Eight Pahnar Im- 

 sion of a C'apucliin Monkey (Ceiai print of a Marmoset (Hapole 

 hiipoleuciis). jacchtts). 



the fingers are much longer and more slender than in 

 the Old World macaque. In consequence of this the 

 bulbs of the fingers are much less developed, so that it 

 was found impossible to get a good impression of them. 

 These featui'es are even more developed in the hand of 

 the tiny American marmosets (Fig. 3), in which the 

 digits are more like claws than fingers, and consequently 

 ■afford only a naiTow and blun-ed impression. A 

 peculiarity of the marmoset hand-print is to be found 

 in the circumstance that the radial eminence has come 

 up to form an arch witb the three interdigital elevations, 

 and that the ulnar elevation and pattern are obsolete. 

 Seeing how comparatively wide apart from one another 

 (both zoologically and geograjihically) are the ordinary 

 monkeys of the Old and New Worlds, it is not a little 

 remarkable that the palm-print of the macaque should 

 be so strikingly like that of the capuchin. 



This similarity (since evei-y thing in nature has a 

 use) suggests tliat the patterns on the hands of these 

 two monkeys are due to the same physiological cause; 

 and we have now to enquire what that cause is. The 

 best clue to the problem seems to be afforded, some- 

 what strangely, by the tails of such of the South 

 American monkeys as ai-e endowed with prehensile power 

 in those appendages. Confirmatory evidence being like 

 wise afforded by the prehensile tails of the American 

 opossums and tree-porcupines, as well as by those of 

 the Australian phalangers. In all these animals the 

 naked, grasping portion of the tail, which is situated 

 at the exti-emity. is covered with papillaiy ridges and 

 grooves precisely similar to those on the hands and feet 

 of monkeys, but invariably arranged in simple transvoi-se 

 lines across the tail, sO' that in the act of grasping they 

 would be parallel to the long axis of the branch around 

 which the tail was coiled. Clearly, then,_ papillai-y 

 ridges are primarily connected with the grasping power, 

 and when they ai-e intended solely for that function 



