Yet another concep­tion from the region of metaphor must be mentioned. It is one which will commend itself to every mind which has been steeped in thoughts of warfare for five years. We are all soldiers now; we think in terms of military affairs. In the case of our hair-streams there are in many regions two forces directly opposed to one another, others in which no struggle has yet occurred, as, in the Great War, Italy was not at one period at open war with Germany.

Between the opposing forces in our small battle-field of the hairy coat there have been waged battles to which those of Mukden, Verdun, the Somme and Arras, are not to be compared in point of time. They are but as one day to a thousand years. On one side of the conflict in our present chosen field the ancient primitive type of the lemur has remained entrenched for some millions of years, until there arose new forces in its descendants on the other side and this changed the war of positions into one of movement. It was indeed “a contemptible little army” which came forward to oppose the ancient barbarian forces of the lemur, long prepared and organised, and these new armies fought under the banner, Habit. In the slowly-formed patterns in many types of mammals we have records of the treaties made after these long struggles and the rectifications of frontier which became necessary. The critic may call these “battles of kites and crows,” and ask What war correspondents were allowed to describe them; but a battle, whether great or small, long or short, is important to the parties concerned, and it is open to us to “reconstruct” the facts of the battle as do the historians on their part, for example, Sir James Ramsay the battle of Agincourt—with tolerable verisimilitude. But in science, especially geological science, the process of reconstruc­tion is much more ambitious and bold than any that is here attempted. Who has not been fascinated, if he has read Sir E. Ray Lankester’s work on Extinct Animals, by the skill and daring with which he conveys to us a vivid idea of the form and mode of life, with scanty data, of the extinct Moa of New Zealand, the great Pterodactyle, Pteranodon, or the Diprotodon of Owen—“the probable appearance in life” of these uncanny but very real inhabitants of the earth in days long past. How skilfully did Owen from a piece of bone seven inches long, sent to him by a gentleman in New Zealand sixty years ago, pronounce it to be a part of the thigh-bone of a bird like an ostrich, and then after a few years had passed, confirmed it by more bones of the skeleton, till the large Moa, extinguished 600 or 700 years ago by the Maoris, lived again before us—an historical personage; or how by the examina­tion of the skull and most of its skeleton the giant marsupial from Australia, Diprotodon, was resuscitated and admired; or again, how from the bones of the arms, shoulder-girdle and fingers was built up the strange body of Pteranodon, the great flying dragon. All of which is the legitimate and approved business of biologists and palæontologists, and this digression is made here to show that my line of treatment of a little subject agrees with that in a greater one; nay, it even proceeds in its explanations of events on the ever valuable principle of Lyell in a still greater one without which to-day geology would be a thing of naught, that is, the principle of explaining changes in the surface of the earth by reference to causes now in action. The objection that one subject is very great and the other very small is not valid; for one as much as the other there are millions of years to be had for the asking. Who in these days hesitates to talk and try to think in millions?—tens of millions of men, millions of soldiers, millions upon millions of money, millions of bacteria in vaccines and millions of money belonging to other people disposed of by the new spendthrift Minister?

From Lemur to Ape.

Returning now to our Eocene lemur we must remind ourselves of the problem before his simple mind and those of his Simian descendants. How was he to change so greatly the direction of the hair on his forearm (Fig. [1]) till it should turn right about face and imitate those great German “victories” of Hindenburg, well called Marshal Rückwarts? The problem lies open in the Figure and receiving no aid from Selection or survival of the fittest, in this little effort, he had to fall back on the eternal and tedious force of habit and use. I am afraid if here I were interrupted by some critic, more learned than wise, by a summary demand on the part of Selection for its share in the result, I should be tempted to reply with the word Φλυαρια employed by George Borrow, forbearing to give the transla­tion of the reply as he gives it. Anyhow, it is a case in which to “listen politely and change the subject.”

Here comes in the aspect of strife between primitive and new obstructing forces in a little hair-stream. The lemur lives in trees and carries on a stealthy nocturnal business, moving on all fours in quest of his daily bread, and no external force or new habit avails to modify the hair-slope on his forearms, and so it remains until some primitive form of monkey, gradually evolving into a primitive ape, brings into the family new habits and customs. Other men and other manners appear in the Miocene Age. Our supposed Dryopithecus fontani becomes more upright in his bodily, and perhaps his moral habits, and spends an increasing amount of his leisure time in the sitting posture; his hands are frequently grasping a bough as he sits and reflects, it may be in a man-ward direction, or, as is more likely, on his last meal of nuts and fruits. But he did not spend quite so much time as Wallace and others think in this futile attitude, for he knew in his way as much as the modern bachelor does, of making his posture comfortable and restful when he was not out at work, and he varied his plans by resting his forearms on his thigh, crouched up and cosy, and doubtless slept much in this attitude. All these bold departures from his lemur-ancestor’s habits had the necessary result of altering the slope of his hair on the forearms, which was now growing as long and coarse as we see it to-day in the orang. In course of milleniums the ancient forces yielded to those of the new armies, and the once normal slope became reversed in a way which shocked the conservative lemurs of his day. It requires little imagina­tion to see how the lengthening thickening hairs on this limb-segment became changed in their direction by friction against the opposing surfaces of the thighs, by gravita­tion, and the frequent dripping of rain when they were held up to grasp a bough. Here then we see at work new forces of friction, pressure, gravita­tion and dripping of rain, turning endlessly and slowly the lemur-fashion into the ape-fashion, with unlimited time for their effectual action. In this stock of Man’s ancestry Selection was taking care of the individual and Habit of the details of his making—two truly harmonious partners.

From Ape to Man.

Another step, and a long one, has still to be taken from the ape-fashion to that of man. Bearing in mind that the lemur-fashion has been totally reversed by the ape it startles one to find that man in his modern fashion has largely reverted to that of the lemur on the front and sides of his forearm. This is clearly shown in Figure [1]. There also you see graphically recorded in the hair of the extensor border of the ulna, a little backward streak, a poor little legacy of fifty pounds from the fortunes of many thousands once possessed by the ape. From the present limited point of view, man is a veritable pauper, and his possessions in this limb-segment may with some irony well be called a “vestige.”

Professor Scott-Elliott in his book, Prehistoric Man and His Story, p. 60, goes rather wide of the mark here in his graphic picture of our rude ancestor and his hard life. He gives too strongly the idea of him sitting asleep in raging gales, in driving rain which is neatly conducted by the thatch of his hair off his skin. As far as it goes this need not be questioned, as a matter of probability, but he states far too broadly “The hair on the arm, even of those civilised men who retain sufficient to trace the arrangement, turns down both upper and forearm to the elbow”[46]—true as to the upper arm, but only true of the forearm in a very narrow streak of hair over the extensor surface of the ulna. The fact is that in every human being, not too old, its course can be traced with a lens. He overlooks also from this protective point of view the fact that the ape or early man, in the position of rest he describes, would have very much the reverse of protec­tion from the “lie” of the hair on his thighs, for this is towards the knee and is well calculated to catch the rain and conduct it carefully, or let it run, into his groins. So the protec­tion theory (under the empire of Selection) is again in straits. But I must not forget my self-denying ordinance alluded to in the Preface, but will show how the ape fashion began to be modified into its present and probably final form in man. Still further changes in the simple habits of the earliest men became frequent, and fresh forces were organised in our mimic battlefield. Gravita­tion gradually ceased to act as the hairs became thinner and shorter. Friction and pressure changed their lines of incidence with the increasing tendency of man to assume the upright posture, for the surfaces exposed to pressure and friction were only affected when the extensor surface or back of the forearm rested on some supporting object, an attitude extremely common in man as we know him now. Then came the opportunity of the primitive barbarian host, the lemur fashion, by a prolonged counter-attack to recover on the greater part of the forearm the ground lost millions of years before by the ape, and then was engraved on the forearm of man the permanent treaty which we have before us to-day.

This small and apparently trivial battle-ground has been described at what may seem undue length, but it is a miniature of the rise and fall of little empires such as here engage our attention, and I make no apology for this to the reader who has gone thus far with me, for, on the principle of ex uno disce omnes, all that follows in other areas of the hairy coat of mammals will be the clearer, and little repeti­tion will be needed.

Note.—Two terms have been used somewhat freely in this Introduc­tion, “vestige” and “normal,” and a few remarks upon them are not out of place, for they are both somewhat ambiguous and apt to be carelessly employed.