Foot of Man.

Fig. 60 S. K. Right foot draw­ing of pap­il­lary ridges made from im­pres­sion.

The point may be best understood by considering the foot of man, of which Fig. 60 shows a good example. The value of the roughened surface of the foot with its papillary ridges can hardly have been great, even in the days when man’s foot was naked, at any rate so little that for him to acquire by a selectional process such a remarkable change of arrangement as we see when we look at the foot of man and of any other Primate involves on our part a tremendous stretch of imagina­tion as to its modus operandi. These low, soft ridges of man’s foot could do little to prevent him from slipping on such surfaces as grass, sand, rock, wet or dry, and from the time when he began to protect his feet with coverings this small value would be further reduced. Underneath his developing plantar arch it would not exist at all, and yet here especially he has changed their direction. As to the papillary ridges, man’s foot has sadly embarked on the pathway of degenera­tion much as his little toe has done. Not only has he here a much simpler arrangement than any ape or monkey, but the individual ridges are blurred and flattened on much of the plantar surface. This comes of his pride in acquiring his human distinc­tion, or title of nobility, of a plantar arch and his coincident increase of pedestrian locomo­tion. On the triple bases of support, heel, ball of great and little toe, the ridges are still strongly marked and coarse; transverse on the heel, whorl-like on the ball of the great toe, and oblique or nearly transverse on that of the little toe. On the rest of the surface they are vulgarly transverse. And I may add that the toe-prints of man are simplicity itself compared with his finger-prints. It would seem that this example of arrangement of ridges on man’s foot is strongly in favour of the hypothesis that they are so disposed by flexion of the foot in walking, and not by some need for preven­tion of slipping under the guidance of selection.