Reasons for Arrangement Observed.

When one discusses the forces in action on man’s hand which are claimed to have thus arranged the ridges, in regard to the question of use and habit, little more need be added as to those of other Primates, and it is because we know more about ourselves than them, and our own palms and soles are available for inspec­tion, that I have taken man as the example.

The main question is the old and now familiar one: “Are these ridges arranged as we see them by use and habit, or adapted for use?” Dr. Hepburn and the orthodox Selectionist would say that, of course, their mode of arrangement is an adapta­tion governed by selection for preventing slipping in the action of grasping an object by the hand, and in the foot for preventing slipping in walking. This does not take into account the question as to how the original slight shifting of the ridges in the earliest man and in lower forms could have had selective or survival value, for example, the insignificant sparse groups of ridges on the palm, sole and tips of the digits in a hedgehog or squirrel. As things are now they do subserve these purposes. But I think this matter of preven­tion of slipping has been much exaggerated, though I may be told that this is a matter of opinion and not a valid argument against the hypothesis.