This embryo is so soft that it is almost like curd in thickened milk, and could be very easily destroyed were it not for a protective device which Nature has employed. It seems necessary that it should be protected with the utmost care. The matter will be better understood if we recall a common experience. Almost everyone has tried to dissolve some substance in water in a vial. If the bottle be filled with fluid to the top and corked it is very difficult to shake up the contents. Even vigorous agitation produces little movement of the material on the inside. If we wish to shake up the solid with water the bottle must be left partly empty. The brain of a human being is protected by just the same device. If it simply lay within the skull the first fall would mash the gray substance against the side of the cavity. To prevent this calamity the bony case is made somewhat larger in capacity than the brain itself, and the space between the two is filled with a watery fluid. This serves to prevent jars and shocks. In the hen's egg the same plan is pursued. The embryo lies on the inside of a bag considerably larger than itself. This sac, called the amnion, is filled with a watery fluid. With such a protection only the most severe shock to the egg would sufficiently jar the embryo to do it any harm. The ordinary experiences of an egg leave it undisturbed.

Every living creature requires a constant supply of food and of oxygen. The embryo is a living creature, and is no exception to the rule. It needs an abundant supply of easily assimilated food and of oxygen. When the hen's egg is first laid the entire contents, with the exception of the little light-colored disk which floats on the top of the yolk, form the nourishment. The disk alone is the living organism. In the earliest stages the embryo receives its food by simple absorption from the yolk. As the chick increases in complexity the yolk at first grows swampy, with fluid trickling here and there through the more solid portions. Thin walls form about these little streams, thus producing blood vessels which cover the entire surface of the yolk. These absorb the nourishment and turn it over to the embryo. As the latter grows in size both the yolk and white diminish. The embryo soon becomes larger than the remaining yolk and is attached to it by a cord filled with blood vessels which enter the chick near the center of its body. The abdominal wall has an opening at this point. One of the later occurrences in the life of the chick, before it breaks through the egg, is to have the last remnant of the yolk and its sac slip to the inside of the abdomen, which then completely closes over it.

As yet, we have seen no arrangement for furnishing air to the chick. At the same point at which the blood vessels from the yolk enter the chick, another set of vessels pass in and out. These are attached to a large flattened bag which floats above the embryo against the upper side of the shell. This bag is called the allantois, and serves as a sort of lung for the developing chick. The shell is porous enough to allow air to pass through it. The blood vessels of the allantois take in oxygen and give out carbon dioxide through the porous shell. The blood thus altered is returned to the chick and serves its life purposes. One of the reasons why the chicken must turn its eggs in the nest is that, if the allantois remain too long in contact with the upper shell of the egg, it will become attached to it and will not thereafter perform its functions.

The embryo thus enclosed in the egg finds its protection in the fact that it is encased in a fluid contained in the amnion. It draws its nourishment from the yolk upon which it lives and the nourishment is transmitted to it by blood vessels. It draws its oxygen and throws off its wastes through the instrumentality of the allantois, which covers it over. Day by day the chick becomes larger, day by day it grows to look more like what it is to be. By the nineteenth day it appears to be complete. Its nervous organization is, however, not thoroughly developed. If removed from the shell the chick still is indisposed to stand upon its feet or to run about. If allowed to remain in the egg until the twenty-first day, the chick will be able to push its beak through the skin enclosing the bubble of air at the blunt end of the egg and get the first breath into its lungs. Now it gives a faint peep, breaks the shell of the egg, and steps out into the open air.

I have given this somewhat lengthened description of the development of the chick because of the light it throws upon the method pursued by the mammals. The features which have been described in the case of the chicken's egg could be as fully observed in the case of the turtle or any of the other reptiles. Mammals are descended from the reptiles of the Mesozoic, and whatever peculiarities there may be in their method of producing their young must be derived from the reptiles. If we wish to know how the earliest mammals produced their young, we can only judge by the lowliest members of the group that live upon the earth to-day. The most primitive of these is the so-called Duckmole, of Australia. This little creature has habits not unlike those of the muskrat. It burrows in the bank of a stream, and makes a nest at the end of the burrow, where it lays its eggs. This is one of the very few warm-blooded, hair-covered animals which still lays eggs. A little higher in the scale stand the kangaroo and the opossum. These creatures keep the egg inside of the body until it is hatched. But this happens in so short a time that the young animal is exceedingly immature and as yet unable to stand the outside air. Accordingly there is a double fold of skin on the abdomen of the mother, covering her breasts. This forms a suitable resting place into which these young are conveyed as soon as they are born and from which they do not emerge for many days. The little creature instantly fastens upon the nipple of the mother, keeping its mouth constantly in this position. At intervals the muscles of the breast force the milk into the mouth of the young, which is still too undeveloped to suck for itself. As it gets older the little opossum or kangaroo emerges from the pouch in the pleasanter part of the day and in the absence of danger. It returns to the mother's pocket as soon as it becomes cold or a cry from its parent warns it of its defenseless position.

These creatures are the lowliest of the class upon the earth. The great majority of all mammals have elaborated a far finer plan, in which the young are retained within the body of the parent until they are quite able to stand the air. The length of this time varies in different mammals from a few weeks to more than a year. The egg must be fertilized before it leaves the body of the parent. If it should fail in this it simply passes out and is wasted. If the fertilizing cell reaches the egg before it has progressed far down the tube it begins its development. The embryo forms for itself the sort of head and tail and gill slits which would have served its fish or its tadpole ancestor. Its limbs develop as little buds indistinguishable from similar buds that would have formed fins for the fish or wings for the bird.

Around the embryo there forms a sac, the amnion filled with a fluid which serves to protect the young mammals exactly as the growing chick was protected. Under the forming creature there hangs a small but empty yolksac. This is an actual remnant, a reminder of the past, when the eggs of the mammals were also packed with yolk and the growing embryo secured its nourishment exactly as does the maturing chick. But a new method has been provided for the mammal, and consequently the yolksac, though it has not entirely disappeared, has no nutritive content for the growth of the embryo.

The allantois of the chick now gains a new development and an altered function. In the case of the chick it floats against the shell of the egg and absorbs oxygen through the shell. Inside the body of the mammal this is impossible, because the air is too far away. No shell is formed about the egg because it is not to be laid. The tube of the parent's body in which the egg lies becomes thickened at the point of contact with the egg. It grows spongy and full of blood vessels. Meanwhile the allantois is also growing spongy. These two tissues are so closely pressed against each other that the blood vessels of the transformed allantois mesh in with those of the thickened parent wall. Thus the blood vessels of the mother are brought into close contact with those of her offspring. Her blood seeps over into the transformed allantois which is now called a placenta. From this it is handed over to the offspring, which thus receives from the mother her blood, and returns its own used blood for enrichment and purification. So the allantois of the reptile has become the placenta of the mammal. In the first instance it served only as an organ of respiration. Now it has come to supply the embryo with rich blood containing both food and oxygen derived from the mother. After the offspring is born this thickened pad breaks loose, and subsequently is also extruded from the body, forming what is known as the afterbirth.

Thus far we have spoken of the change in the method by which the young are brought to such a stage of development that they can stand the outer air. One of the improved differences between the mammals and other animals lies in the method by which they nourish their young for some time after birth. The very word mammals signifies an animal who is in the true sense of the word a mamma. This name for mother is given to her because of the fact that she possesses what are technically known as mammary glands, or, in simpler language, breasts. It would seem as if here we had an entirely new organ. No other animal gives nourishment to its young in such fashion; all mammals do. What is the origin of the habit? How did the organ arise?

A part of an animal's body that has the power to gather material from the blood and pour it out in the shape of fluid is known as a gland. Sometimes a whole organ does nothing else. Sometimes small glands are scattered through, or over, the surface of another organ. There are two kinds of glands in the skin of the mammal. The best known and most frequently thought of are those which pour out the perspiration. These have a double function. In the first place they assist in keeping the temperature of the body uniform. When we are too warm they pour out a watery fluid over the surface of the body. If the air is dry enough and our body not too closely protected by clothing, this perspiration passes off in the form of vapor. All evaporation requires heat, which in this case is extracted from the body. So soon as the temperature returns to its normal level the flow of perspiration ceases. The other function of the sweat glands is to take from the blood some of the waste matters of the body and pour them out upon the surface. This is done in order that the body may free itself from substances which, if they were to accumulate, would have a poisonous effect upon its action. It is this function of the sweat glands which makes it necessary for us to bathe the surface of our bodies with water. Dirt, in the ordinary sense of the word, is not harmful to a sound skin. Our reason for bathing is really to remove the wastes which we ourselves have poured upon the surface of the skin. These, if allowed to remain, soon decompose, like all nitrogenous substances, and become very offensive. They may then be reabsorbed into the skin and nature's effort to throw them off has been in vain. These glands, since they contain waste matter, could not possibly yield food for the young. They would poison and not nourish. Hence, whatever the breasts may be, they are not altered sweat glands.

There is another set of organs in the mammalian skin. At the base of each hair lies an oil gland. The function of these is to pour out a substance which spreads along each hair and over the surface of the body. The outside of the skin is always dead, and would easily crack were it not for the constant secretion of this oil. In winter, when the blood circulates less freely and these glands consequently pour out less oil, the supply frequently runs short. If what little is poured out is too frequently removed by washing, the skin becomes brittle, and, on bending a joint, the epidermis cracks. The gloss of the hair is due to the oil thus poured out. This oil becomes one ingredient in the milk produced by the transformed gland. But there is another important constituent. When one does unaccustomed manual work the ordinary result is the formation of a blister. The epidermis, or scarfskin, becomes detached from the dermis, or true skin, and the space between the two rapidly fills with the fluid portion of the blood, known as lymph. The fact that no blood vessels have been broken in this detachment results in there being no red corpuscles in this fluid. Wherever a cavity forms in the body lymph is liable to enter it.

The milk glands of the mammals are modified oil glands. The fluid which they now pour out is no longer exactly the old oil with the addition of the lymph. Undoubtedly in the past the first milk was more like this simple mixture. There seems no doubt that the breasts of to-day are the enlarged and modified oil glands of earlier mammals. In one of the most primitive of our mammals the young simply lick certain bare spots on the surface of the mother's abdomen. As higher forms arise there develops a smaller or larger mound with a distinct projection, about which the lips of the offspring can easily fasten. Lamarck would have said that the suction of the infant had produced such a mound, and that this had been transmitted to later offspring until it had grown to be the highly developed organ we now find, for instance, in the cow. Since, however, we have come to disbelieve in the transmission of acquired characters, this explanation will no longer serve. We must content ourselves with saying that, by whatever accident the nipple arose, the success of it when present determined its selection by nature and its consequent persistence. With increase in its function has come increase in the size of the glands. Lower animals which, like the hog, produce a large number of offspring, possess a large number also of these glands. With the diminishing number of young and greater care of them as we rise in the scale has come also a diminishing number of breasts in the female. Whether those on the front of the body should persist, or those on the rear, depends upon other factors in the life of the animal. Hoofed animals, perhaps because their best weapon is the hoof and they can there best protect their young, have retained them in the rear of the body. In the group of animals known as the primates, including monkeys, apes, and man, the habit of holding the young in the arms for protection has determined the persistence of the breasts upon the chest rather than the abdomen.

It is interesting to notice that the habit of the elephant of protecting its young by means of its tusks has also resulted in a similar position of the milk glands.

That the primates had once a larger number of offspring is confirmed by double evidence. Even to-day the number of children at a birth is often two, sometimes three, rarely four. The day before this was written came the report of a case of five children at a birth, all of whom seemed sound and all of whom lived. Still more direct evidence is found in the fact that occasionally in the human female there are two pairs of breasts, and very rarely three pairs. These are then disposed in a double line down the front of the body.

The new plan of caring for the young is one of the priceless heritages of the higher animals. As we rise in the grade of life the number of the young produced at one time steadily diminishes, while the care spent upon them increases. The shad may lay four hundred thousand eggs and trust them entirely to their fate. The sunfish will lay a thousand, by no means all of which can be fertilized, but it guards them somewhat after deposition. The toad lays several hundred, stores them with a considerable amount of nourishment, and protects them by a bitter deposit of mucous. The turtle has reduced the number of eggs to perhaps a score. Each of these is supplied with abundant nourishment, so that the young may develop to considerable size and activity before emerging from the egg. This material is enclosed in a firm protective shell and hidden away from sight by being buried in the ground. In the mammals comparatively few eggs are produced at one time. These are fertilized within the body of the parent, are attached to the parent, and absorb her blood. No shell is needed because nothing will kill the developing offspring that is not likely to injure the parent. Not only do the young feed upon the blood of the mother up to the time of birth, but they are practically dependent upon this same blood after birth. Though they do not take it directly from the veins, the milk is, none the less, the transformed blood of the mother. This assures the young of food as well as of protection. Best of all, the young are provided with the companionship of the mother. Now for the first time animals learn by example. Heretofore they have been born with a nearly undeviating instinct; now intelligence begins to arise. They can imitate their mother. Heretofore no acquired characters affected the young. In the mammals, although the young cannot inherit the acquired habits of the parents, they can get them by imitation, which serves nearly as well.

There is, however, a more wonderful advantage that comes from the close attachment between mother and offspring. This intimate relationship brings about an affection of the mother for her young heretofore unknown in the animal world. It is somewhat paralleled among birds, but here the care of the nestling is less intimate, far less maternal, than the care of the mammal for her young. As the number of the young grows less and the care taken of them increases, the intensity of the affection also increases. By the time we get as high as the dog or the cat this fondness becomes a fierce, self-sacrificing love. When we come to man, with his high intellectual powers, with his deeper moral sense, we find a wonderful change. This love of the mother for her child has grown into the finest emotion possible to the human heart. It no longer is confined to the dependent life of the child, but follows the offspring through its entire life, guiding, guarding, shaping its destiny, handing on to the child the treasured wisdom of the race. Influenced by the example of the mother, the father comes to have a love for his children. It is not so strong as that of the mother, nor so utterly unselfish, but it is still a noble and exquisite love. Developing in a different direction, the love of the mother for her children grows as civilization advances, and spreads over the father of those children as well. Again reflecting her love, the man finds himself filled with a new feeling for the woman. It is never as unselfish, as free from desire, as is her love, but it completely transforms his relation to her. What has been with him simply desire is ennobled and enriched until it becomes the finest passion of his life, absolutely transforming him, in relation to her, from a selfish brute into a tender and life-long companion. So utterly does the love thus engendered transfigure human life that when we seek to express the divine nature in human terms, and these are the only terms we know how to use, the richest revelation that has come to us is the conception taught by the Master that "God is Love" and that "as a father pitieth his children, so the Lord loveth them that fear him."



CHAPTER VIII

THE STORY OF THE HORSE

Ever since men have been familiar with the idea of evolution there has been a temptation on the part of the zooelogist to draw up pedigrees expressing the relationship between the various groups of the animal kingdom. The impulse is natural, and, if the resulting tables are not accepted with too much confidence, the result is not undesirable. The truth of the matter is that all of these pedigrees are more or less hypothetical. They simply show what connection seems most likely. In all of them are spaces filled with doubtful names. Each addition to our acquaintance with the past history of animals necessitates revision of our tables. The student of fossils, trying to rebuild in imagination the world of the past, finds himself often strangely unable to link these animals together. The result is that the more we know of fossils, the more distrustful we become of the easy connections we have been making between groups. Accordingly we are more than commonly pleased when we find the clear indication of a genuine pedigree, actually illustrated by real examples, following each other in time through the geological history. A few of these lines are gradually becoming plain, and none of them is clearer than the pedigree of our familiar and much loved horse. The example is a particularly interesting one, not only because of our affection for the animal, but because the horse originated in all likelihood in North America on the land occupied to-day by our Western plains. As though he loved the country of his ancestors, he returned after having circled the globe, and once more went wild in the home of his forefathers. The problem was first worked out in Europe and later elaborated in this country. Now the history gets its finest expression in the American Museum of Natural History in New York City. The collection of fossil horses in that institution surpasses in completeness and in excellence of mounting and of sympathetic restoration any similar collection representing the ancestry of any other animal in the world.

In the table of Geological Times, given in chapter six, the era of recent life known as the Cenozoic is seen to occupy something like five million years. This figure, as was previously suggested, is very uncertain, and may be three or may be six, but is safely represented in millions. Through most of this time stretches what is known as the Age of Mammals, the Tertiary Age. Its close, occupying only the last few hundred thousand years, is known as the Age of Man, the Quaternary. Through perhaps three or four millions of these years stretches the known pedigree of the horse.

When we go back to the early Tertiary we find a forest, with trees that shed their leaves, interspersed with glades, in which already the grasses were beginning to be developed. This state of affairs had existed but for a comparatively short time, geologically speaking. It had come only in the latter part of the preceding era. Lake and swamp, meadow and forest intermingled to make a rich and varied scene. Slowly the land toward the western side of North America lifted itself into plateau and mountain range. Slowly the westerly winds began to be cut off by the barriers thus raised across their path. As they swept over the plateau and down into the eastern plain their moisture came to be diminished. Gradually a very different state of affairs set in. The ground became harder, the forest became sparser, the plants became higher and firmer, the grasses tougher and more wiry, and, by the time the Quaternary arrived, a condition probably even drier than that of to-day existed over our western highlands. Throughout this long change, spread over millions of years, a creature which has become our horse steadily persisted and steadily advanced. Side lines developed which finally disappeared, but the main line kept on, and when the Quaternary came the horse arrived with it. Many of the skeletons in this series were known before it was realized what they were. As time went on and intermediate forms were found, it became possible to recognize these as ancestors of the horse and to assign them their proper position in the family tree.



The earliest of the forerunners of the horse with which we are acquainted would certainly not be recognized as such by any but the most careful student of animals, if we could see him to-day. He stood not higher than a fox-terrier dog, though his shape was very different. But he would probably be more likely to be classed with the dog than with the horse by the hasty observer, for he walked with four toes of each foot upon the ground as the dog does to-day. Like the dog, he had hanging at the inner side of his front foot a little useless toe. He was long in body, comparatively short of leg, a little long of head and neck, and distinctly long of tail. His grinding teeth had points on them not unlike a pig's, and possessed no apparent resemblance to the wonderful curved and ridged surfaces seen on the teeth of the modern horse. What his skin and hair were like can only be conjectured. In the restoration which Mr. Knight has made, at the suggestion of Professor Osborne, an interesting inference has been drawn. That he was a creature of the forest is suggested by his spreading toes, which would keep him from sinking in the soft soil. It is consequently surmised that he was dappled with spots which allowed him to rest unnoticed on the sun-flecked floor of the forest. Mane he had none, and his tail was probably tufted slightly at the end with hairs, which were increasingly short as they approached the top. He had no forelock, and the hair along the ridge of his neck was a little longer than the rest, and stood erect. Browsing about on the soft and tender herbage of his woodland home, his teeth had as yet no tendency to become specialized. The molars had mounds upon them, developing, perhaps, more into the shape of the points of the hog's, but even still quite generalized teeth. His main enemies, from whom, perhaps, he could with little difficulty escape, were creatures related to the hyenas of to-day. Perhaps, like their modern representatives, they preferred eating their flesh tainted to exerting themselves enough to capture and kill their prey. By the time we advance a little further into the Tertiary, though still in its early portion, a remarkable change has already come about. The fifth toe, which in the earliest horse hung upon the side of the front foot, has completely disappeared. The change in the hind foot has gone still further. The hind leg in many animals evolves more rapidly than the front. The heavy work of running is always done by the hind feet, while the front feet serve rather as a prop to keep the animal from falling than as the actual means of locomotion. Hence the hind feet and the muscles of the hind quarters are almost always heavier than the front. Possibly on the front foot the little fifth toe was less of an obstruction, and persisted after the early horse had lost the corresponding toe on his hind foot. This process has gone on still further in this second stage, and the hind foot has but three toes, while the front still has four. This is not the only advance. Already the middle toe of the original set of five is becoming emphasized. The weight is thrown more forcibly upon it, as with the human foot it is upon the inner or big toe. The middle toe is growing larger and larger, and the nail upon it is spreading around it and is growing firmer. The creature, too, is standing more nearly upon his toes; his legs are getting longer; he stands higher from the ground, and now has come to be the size of a hound.

We can only surmise why this creature should have undergone such a change, but the presence of flesh-eating animals having the size of a fox, and presumably of the fox's swiftness, probably tells the story. The little bands of early horses, pursued by their carnivorous foes, were slowly modified into swifter creatures. It is not so much that running made them fast, as that the slow ones were continually being caught. If this process of constant elimination of the slow members of any herd is kept up long enough, the group will necessarily develop speed. As time goes on, of these early horses those which happened to have longer legs and stood higher upon their toes won in the race, and handed on their qualities to their long-legged descendants. As the animal rose upon his toes, the inner toe, corresponding to our thumb, was first raised off the ground and rendered useless, while a similar change came over the corresponding toe on the hind foot. The hard work of running being done on the latter, this superfluous toe was more detrimental there than on the front foot, and disappeared, consequently, more rapidly. In time, however, it also disappeared from the front foot. Gradually the further elevation of the foot lifted the toe, which corresponds to our little finger, off the ground, and this now disappears also.

With increasing toughness of the grasses, as the climate becomes drier and the region more elevated, the teeth of the horse are given harder work. The points begin to spread into ridges and to unite with each other in such way as to form the crescents, which are later to be so characteristic of the teeth of the modern horse.

By the middle of the Tertiary this ancestral horse has risen in height until he is taller and heavier than a setter dog. Three toes are found on each front foot. The middle toe is getting constantly more developed, though the smaller toes are evidently still of use. The ridges of the teeth are quite crescentic now on the outer side, and becoming better adapted to the evidently firmer food which the creature is obliged to eat.

As we come toward the end of the Tertiary, the development which had been all pointing in one direction has advanced very much further. The creature now would be undoubtedly recognized by anyone as a horse. The legs are longer and straighter; the middle toe has become the only useful toe, though on each foot a smaller toe, slender and probably useless, still hangs on either side. Two similar useless toes to-day hang at the back of the foot of the cow, which is now walking upon her two toes, which give her the appearance of carrying a cloven hoof. That is to say, the first toe on the foot of the cow has disappeared, the second and fifth hang useless and much diminished at the back of the foot, while the third and fourth are both well developed and serviceable in walking.

The late Tertiary horse has grown to be the size of a burro of to-day, though probably it was a little more slender. The teeth are quite horselike, both in shape of the crescentic ridges on their surface, in the length of the teeth in the jaw bone, and in the fact that the crinkled edges of enamel on the upper surface are protected on either side by dentine or by cement. These surfaces, being softer than the enamel, wore away somewhat more rapidly and allowed the sharp edges of enamel to stand up in ridges. This plan increases the grinding power of the teeth.

With the oncoming of the Era of Man the horse reaches his modern splendid development. During the early Quaternary the horse was perhaps in some of his representatives a larger creature than he is to-day. Each foot now has but a single toe. The nail has spread around firmly and heavily, until it has become a splendidly developed hoof, permitting the animal to travel with speed over firm and often stony ground. The side toes have disappeared completely from the outside of the horse's leg, although upon removing the skin it is easy to find the long splints, which are the remnants of toes, which have not yet quite disappeared. His heel has been lifted in the air until it is eighteen inches off the ground, and he is standing like an expert dancer upon the tip of his toe. The body of the horse thus being lifted far off the ground, a new development becomes necessary. All through the growth of the creature the neck and head have been obliged to lengthen correspondingly. Every animal must be able to bring its head down to the level of its feet in order that it may drink. Various animals use different methods to accomplish this result. The giraffe, with his enormously long legs, has a correspondingly long neck, which lowers his mouth to the ground. Even with this extended neck the giraffe's legs are so exceedingly long that he is obliged to spread his front feet when he wishes to reach the ground with his head. The elephant has pursued exactly the reverse plan. Using his tremendous head as a battering ram in fighting, and using his enormous tusks both in battle and in uprooting young trees, a lengthened neck is absolutely out of the question. Furthermore his front teeth have grown so prodigiously that they would interfere with his getting his mouth to water. Accordingly, his nose has lengthened its tip until it reaches the level of his feet, and this nose becomes to him the main organ of grasp and of touch. To drink, its end is inserted in the pool and water is drawn up the nostril. If the animal were to attempt to draw it all the way back into his throat, it would inevitably strangle him by getting into his windpipe. Accordingly, when the nose is well filled with water, the tip of it is inserted in his mouth, and the water discharged by a quick puff. The horse has taken a method intermediate between these. It had moderately lengthened both neck and head in order to get to the ground with its nipping teeth, and thus to gather the grasses which serve as its principal food.

The mammalian teeth, while of four kinds, really in most animals serve but two purposes. The front teeth consist of the incisors and canines, and are used for biting. The hind teeth, consisting of premolars and molars, are used for grinding. In the horse, the jaw has lengthened between these two sets, carrying the biting teeth far forward of the molars. It is this gap in the row of the horse's teeth which makes it possible for us to insert the bit into his mouth.

Now comes a strange accident into the life of our American horse. Creatures of the same kin had been evolving in Europe and Africa, but the developments are more distinctly horselike, it would seem, in our own country. Then for some reason the horse disappeared completely from American soil. Doubtless two things happened. First of all, some of them migrated across a stretch of open country which then connected America with Asia in the neighborhood of Bering Strait. These creatures spread first over Asia and then over Africa and Europe, leaving their skeletons scattered over this enormous stretch of country. Asses and zebras are still found abundantly and widely scattered, but the wild horse of to-day is seen only in western Asia. What happened to those who remained in America we shall possibly never know. Some surmise that a fly not unlike the tsetse-fly of Africa killed them out. Perhaps the members of the cat family, which are steadily growing larger and fiercer, fed on their young if not upon the older ones, and exterminated them. Perhaps the Glacial period which followed was too cold for them. But, whatever may have been the cause these horses died out not only in North but also in South America, to which country they had spread.

The old world horse was the companion of man. The skeletons of those found with early man in the caves of Europe look as if the horse had been a creature to draw man's burdens and to serve him for food, rather than to bear him upon its back. Its roasted bones are often found about the old tribal fires. Upon the discovery of the new world the Spaniards brought with them to Mexico and to the Mississippi Valley the horses which carried them in their battles against the Indians. In the course of these frays many riders were killed and their horses roamed wild. Slowly they made their way to the western plains; gradually they became tougher and more wiry; their diminished hoofs learned to catch more carefully in the rocks of their mountain home; and the mustang and bronco of more recent years are the descendants of the little dawn horse, whose dainty skeleton is found in the rocks over which his later descendants, after a long stretch of perhaps four million years, are now running.



CHAPTER IX

EVOLUTIONARY THEORIES SINCE DARWIN

In considering the value of Charles Darwin's work and its permanent effect upon the thought of mankind, we must be careful to distinguish between two phases of his effort. It was his aim to prove two propositions: first, that there is such a process as evolution; second, that he had discovered the method by which evolution is accomplished. Before his time there was no general agreement as to the fact of evolution. People generally thought the idea absurd, as well as irreligious. All previous efforts on the part of advanced thinkers to persuade mankind of the truth of evolution had been nearly without effect. Among the early philosophers the whole idea was purely speculative. They made no attempt to prove it, and the conception was without influence upon the thinking of the ordinary man. This remains true until the time of Lamarck. This French genius succeeded in persuading not a few people of the validity of the idea of evolution. He probably could have convinced many more had it not been for the hostility of Cuvier. Accordingly, Charles Darwin's "Origin of Species" fell upon a world entirely hostile to the idea, when it thought of it at all. Within fifty years of the publication of this wonderful book, probably the entire scientific world is agreed that evolution, in some form or other, is the undoubted solution of the mystery of creation. The materialist may think of it as a mechanical process relentlessly working itself out without design or purpose. The theist will accept it as the plan by which Eternal Power steadily works. The devout Christian or Jew will see in it God's method of creation. The idea of development has penetrated every science that has to do with animals or man. It is even beginning to influence such inorganic sciences as Physics and Chemistry. We now hear of the evolution of the elements, and the evolution of forces. The world has been persuaded that evolution is true, and this is primarily the result of the work of Charles Darwin. It is astonishing that so great a revolution should have come in so short a time.

The other phase of Darwin's work was his attempt to find the agent which is bringing about the actual transformation of animals and plants. As we have seen in the preceding chapters, it was his idea that natural selection was the efficient agent which constantly eliminated all unfit variations, leaving only the best to carry on the work of the world and to reproduce their own fit kind. Many biologists since his time have doubted whether unaided Natural Selection will account for the constant advance in organisms. This is the part of the work which is often seriously questioned.

Weissman and his co-workers have contended that this unaided principle will serve. Most biologists have asked for some more efficient cause, and assert that selection does not account for the appearance of variations, but only for their preservation, and that any valid theory of evolution must show how variations originate. It is chiefly in this respect that Darwin's work has failed to satisfy many later biologists. When we hear a scientist speak of Darwinism as being dead, this is what he means. He does not think evolution false, but believes that Natural Selection is not sufficient to account for evolution. There are three main difficulties involved in Darwin's theory. The chief defect lies in the fact that selection cannot originate varieties. In all his earlier works Darwin simply accepted variations as he found them. He was content to say that all species varied constantly, and in every direction. He gave no theory to account for variation. Whenever he took measurements of the dimensions of any large series of objects of the same kind he found these measurements to vary, apparently, in all directions. Upon the facts of these variations, and without accounting for them, he built his own theory of evolution. He realized his weakness, and acknowledged it in his book. He probably did not anticipate how insistently later biologists would demand an explanation that would account for this variation. In his later work, responding to this criticism, Darwin originated a theory which he called Pangenesis. He believed that when an adult animal had responded to his environment and acquired a new character he could transmit this character to his offspring. At that time no one doubted this fact. The whole theory of Lamarck was based on the assumption that this could be done. Darwin suggested that every organ of the body threw off minute particles, which he called pangenes. These little bodies, carried by the blood, were taken up by the egg cells or sperm cells, and the latter cells determined the future development. Consequently, the character of the new individual was determined by the parental pangenes. In this way the gain acquired by one generation could be passed on to the next. This theory was purely speculative. He never pretended that there was the faintest corroborating evidence visible to the microscope in the organ, in the blood, or in the germ cell. It was not an accounting for what is, but for what it seemed possible to him might be.

This theory of Pangenesis, in the shape in which Darwin promulgated it, has dropped out of consideration almost entirely. DeVries of recent years has revised it, but with distinct modifications, and most biologists pay no attention to it.

There is a school of biologists, headed by Weissman, who have come to be known as Neo-Darwinians. These men have insisted that Natural Selection, if properly understood and developed, is quite sufficient to account for the fact of evolution, including the appearance of variations. Weissman himself is a microscopist of more than common skill. He is thoroughly accomplished in the most modern methods of killing, fixing, staining, and mounting. This worker's acquaintance with the intimate structure of the cell is probably as great as that of any other man in the world. Weissman asserts that he has seen inside the nucleus all the machinery necessary to explain how the father hands over his qualities to his children. He insists, equally strongly, that this process is such that no father can hand to his child any qualities which he himself did not have at least in potentiality at his birth. Everything the individual acquires during his lifetime is his own possession, which he may use and develop to the utmost extent, but it dies with him. His children, born after he possesses it, can no more inherit it than those born before. Weissman expressed this in his famous statement that "There is no inheritance of acquired characters." The biological world has had no shock equal to this since Darwin's time, and there are few other questions to which scientists to-day return with such constant vigor.

If what Weissman says is true, that no variation or development which comes to an animal during his lifetime can be transferred into his own germ cells and handed on to his children, then it becomes evident that we must find some cause of variation that acts within the germ cells. This is the difficulty which Weissman meets. He says that there are small particles in the nucleus of each cell; that these particles which he calls determinants decide the form and the course of development of that cell; that when that cell divides to produce another cell it gives to this other cell one-half of each determinant. As a result the second cell grows to be like the first. This tells us why offspring are like their parents. There is nothing in the theory thus far to show us why offspring are not exactly like their parents. In other words, there is no accounting, thus far in the theory, for variation. When the biologist studies carefully the history of an egg while it is being formed, he sees that at one stage in its development it throws away not one-half of each determinant, but one-half of the determinants. When an egg does this, it deliberately casts aside one-half of the possibilities of its own development. This throwing away is quite as effective for all its descendants. Any ancestral quality now lost is lost from the line forever. In the formation of the sperm cell set free by the male a similar throwing away of one-half the characters has taken place. The egg cell and the sperm cell fuse together. There are as many possibilities now as there were in either parent, but not all the potentialities of both parents. Half the possibilities of each have been thrown away, and hence cannot appear in the offspring. By this constant process we get, in every generation, new combinations of qualities. This is the main cause, says Weissman, for variations.

There is, however, another possible cause. Each cell has enough determinants in it for many individuals, and it seems to be more or less a matter of accident which qualities shall come out. It has been suggested that as an egg lies within the gland, a blood vessel may bring blood to it in such way that a determinant, lying in a certain position in the egg, may get the richest supply of blood, and hence develop at the expense of the less nourished determinant. By these two methods variation comes into an animal's life, if Weissman and his school are to be believed.

This is a serious blow, if true, to many theories of evolution. The great mass of evolutionists still feel that somehow there is an influence by which the environment produces variation. How the influences of the surrounding world can get down into the body of the parent and affect the egg is unknown. This is freely confessed by every biologist. All are agreed that Weissman's work has made us cautious, and prevented our lightly accepting a belief in the influence of the environment. Yet it is felt by many that slowly and gradually, in the long run, the germ is affected in the same manner as is the body of the parent. In other words, even those who are not followers of Weissman, have accepted the idea that there is little inheritance of acquired characters. Yet they return to the belief that somehow, in some way as yet unexplainable, the main cause for variation in animals lies in the situation in which they live, and tends toward better adaptation to that situation.

Whether men with this conviction are merely reactionaries whose confidence is returning, or bold thinkers whose views will ultimately prevail, time alone can tell.

A second strong objection was brought against the theory of Natural Selection. Darwin declared that small variations in favorable directions are selected and become the starting point of new and better things. It is soon seen, however, that the effect of unaided Natural Selection would be but to mix new departures with the old forms, and soon swamp out any progressive tendency. Whenever a genius appeared, instead of finding a corresponding genius with which to pair, it mated with the average of its own species. Hence its offspring were nearer the average than it was, and their offspring still nearer. Thus whatever advantage the genius originally possessed gradually sank into the common level.

It was Moritz Wagner, a German naturalist, who first insisted that if favorable variations were to amount to anything these possessors must not only mate with others of their same kind, but must also be prevented from mating with the old average group. Accordingly, the belief arose that, under ordinary circumstances, variations returned to the common level. Wherever a varying group became separated by any barrier from mating with the rest of its species, and had only its own kind to pair with, a new species sprang up. This barrier might be a desert, or an impassable mountain range, an arm of the sea, or anything else that the animal could not, or would not, cross. Isolated in this way, the little group that had an advantage in a different direction could develop its tendencies, and a new species would be made of what had been previously only a geographical race. In this matter of geographical isolation Wagner is very strongly supported by the American zooelogist, David Starr Jordan, who believes that no two closely related species of animals ever occupied the same geographical area. Both Wagner and Jordan are ardent admirers of Darwin and his theory of natural selection, but both believe that it is necessary to add the idea of isolation in order to make natural selection effective.

George John Romanes, a British naturalist, has added to Wagner's idea of isolation, the expanded conception that there may be isolations that are not geographical. For this phase, Romanes has coined the term physiological isolation. Something in the structure or habit of the animals with the new variation prevents them from mating with the older type. Occasionally it is a difference in the structure of the reproductive organs themselves. This, however, is not the only possible divergence. The mating season in one group may come earlier than that of the other, or may come during the day, while the main group is in the habit of mating at night. Anything which keeps some members of a species separate in their mating from the rest, will result in the course of a longer or shorter time, says Romanes, in the formation of a new species.

A third great objection was raised against Darwinism. The theory said that only useful variations were selected by nature. It was asserted by objectors that the earliest beginnings of any variation must be too slight to be useful, or as the term went, to have selective value.

It has been noticed by a number of naturalists that certain animals seem to carry the development of a peculiarity altogether too far. It is seen for instance that in the Irish Elk, which has for some time been extinct, the horns were so enormous as to be a source of danger rather than of assistance to their owner. It was said that the tendency to produce heavy horns had gained, as it were, a sort of momentum, and that this impulse had carried the development beyond a safe limit. The Irish Elk became extinct because his horns were too heavy. During the Mesozoic period the reptiles grew too large. They seemed to have carried size to a point at which it became a danger instead of a help. They completely passed out of existence, leaving behind them only very much smaller reptiles.

Eimer, of Germany, has based on facts like these his theory of Orthogenesis. He says that variations in animals are not indefinite and in every direction, but that they follow along clear and definite lines. These lines, in the case of the elk and of the Mesozoic reptiles, developed too far, but ordinarily the effect of such a tendency is distinctly beneficial to the animal. It particularly assists in carrying on for a time the variations which have not yet become useful to the animal. It has always been difficult on Darwinian principles to understand how the beginnings of the useful variations could be selected before they were strong enough to be of actual value to the animal. This tendency to variations in certain directions instead of at random would account for such early development. This theory of Orthogenesis has not figured very strongly in the history of the movement, but it recurs at intervals.

Both in America and France there is a constant tendency on the part of zooelogists to return to the Lamarckian idea that it is the use of an organ that develops it, its disuse that makes it fade away. This is undoubtedly true of the individual, and although Weissman insists that it is useless to the species as a whole, many zooelogists are slow to relinquish entirely the idea that somehow these favorable developments become reproduced in the offspring.

Professor Cope, the American paleontologist, was a strong believer in the effect of activity, both upon the individual and upon his descendants. He believed that the insistent beating of the foot of an animal upon the hard soil of the drying Tertiary plateau, had influenced the production of a firmer nail, which spread around the entire end of the toe and made the hoof of the ungulate. He believed that the use of the teeth in grinding produced a stronger and better molar tooth, and that the offspring shared in this advantage. Since Weissmann's time, however, every Lamarckian feels it necessary to suggest some method by which the altered body of the parent can produce modifications in the germ plasms from which the young are to spring. One of our later biologists begins to talk of some effect comparable with wireless telegraphy or induced electricity. He believes that organs in the adult, not necessarily by direct action, but by action from a distance, may alter the germ. Of this, there is no proof at present. Others have suggested that just as the ductless glands pour into the blood chemical substances which materially affect the growth and development of other portions of the body, so similar enzymes, or other chemical substances, may be sent into the blood, which subsequently bathes the germ cells of the coming generation and produces the change. But of this, again, there is no proof. We may believe that acquired characters are transmitted, but we certainly do not have a very clear idea as to how it can be done.

One of the strongest objections to Darwin's idea of evolution by natural selection of small and favorable variations, is that the process is too inconceivably slow to account for the enormous progress which has been made. The answer has always been that our observation ran back so short a time that we really have no clear idea of how rapid evolution may have been. Again, it has been answered that transitional geological periods, in which there is much change in the physical geography of a country, will produce more rapid evolution than we at present are experiencing.

Hugo DeVries, of Amsterdam, believes he has found the answer to this difficulty. Outside of his botanical garden an American species of Evening Primrose had run wild. In looking over a number of these plants he found, every here and there, certain peculiar members of the species. They differed noticeably to the practiced eye from the rest of the group. When they were planted and crossed with each other, and the resulting seeds were again planted, the peculiarity remained constant in all the members of the collection. Here then we have a true variation, not large in amount, but at the same time quite definite, and which from the first remains true. Here are the beginnings, says DeVries, of new species. They are true from the first; they can live among other members of the species and still come true; they do not need isolation, at least in Wagner's geographical sense. These forms DeVries calls mutations. It is his thought that a species may run along uniformly for a long time when, from some cause which he has not determined as yet, instability comes into the species and it varies in quite a number of directions. Each of these variations may be the starting point of a new species. DeVries believes that he has at least half a dozen mutants of his new Evening Primrose.

This theory of Mutation has been eagerly seized upon by many botanists. The zooelogists have not accepted it quite so enthusiastically. If this is the chief method by which species transform, it seems strange that we do not find more mutations than we do. Perhaps we do not look carefully enough; perhaps we shall find them a little later. Just at present it seems premature to believe that all evolution is by mutation, although quite possibly some of it is. The main apparent advantage of mutation is that it hastens the time in which a new species may arise.

There are certain difficulties which run back into the problem, and which must first be reasonably solved before a clear understanding of the idea of evolution is possible. The first of these is as to the nature of life. What is life? The reply of the biologist will probably be that so far as its material side is concerned, it must be answered in terms of physics and chemistry. As to any side not material, if it have any such side, science says that the chemist can have nothing to say. The chemist may have an opinion of his own based on some other ground than his chemistry, but so far as he is a chemist, he has no opinion. The chemical side of life is being very carefully and very fully investigated. We are certainly being brought nearer to the borders of the living substance. We are rapidly gaining fuller knowledge of the physical and chemical processes which constitute life, or with which life is always associated. If we gain this knowledge we shall be in better position to solve many of our other problems. Even then there is a problem which preceded and which will possibly always defy solution. How did life originate? Has it developed out of chemical and physical activities which we know as heat, light or electricity? If so, what were the conditions under which it developed? If we understand the nature of life, and the conditions under which it developed, we may be able to produce it at will.

A few scientists may hope dimly that this will be attained. I suspect a great majority believe it to be impossible, and that the question as to whether life evolved upon this planet, or this planet became infected with life through meteoric dust from some other center, will forever remain an unsolved problem.



CHAPTER X

THE FUTURE EVOLUTION OF MAN

The disturbance of mind created by the publication of Charles Darwin's "Origin of Species" would have amounted to nothing if the theory had been applied to the lower animals alone. Few people would have disputed that a cow and a buffalo had descended from the same ancestor, or that monkeys and apes were of a common blood. The whole theory would have been looked upon by those outside the biological world as entirely an academic question, in which they had little concern, and less interest. But within this century the scientist has so persuaded the world of the unity underlying the activities of the universe, that so soon as a principle is established men begin to run it out to the very end. Everyone knows perfectly well that if it could be proved that the dog and the horse had a common ancestor, still more if it could be made apparent that the dog and the frog and fish had sprung from the same stock, then there could be no question of what would be the final application of the theory. Man himself could be no exception to the law. So the battle dropped at once upon this most interesting point, and around this center the contest has waged.

What is the origin of man? Who are his ancestors? As soon as we ask the question there is no doubt whatever as to the answer, if we accept the principle of evolution. Our only means of judging relationship between animals is by the similarity of their structure. As soon as we come to examine the other creatures even in the most cursory fashion, there is only one group which in any close degree resembles the human species. Our nearest relatives among living animals must undoubtedly be the apes. Some little distance farther away stand the monkeys, and, structurally speaking, there is more difference between a monkey and an ape than there is between an ape and man. The gap between man and his relatives of this group, known as the primates, is a mental, not a physical one. While his brain and his mind have developed far beyond theirs, the rest of his body is comparatively close to that of an ape.

Probably no one can face the possibility of his being descended from creatures not unlike the ape, without feeling a stirring sense of repugnance. The least aristocratic of us hesitates to name in the line of his ancestry creatures so unlike himself as the members of this group. It seems to us impossible that we should have descended from creatures as lowly as they. If evolution is true, these are among our near ancestors. Back of the group of primates lies a far less developed set of insectivorous animals, behind them the reptiles, behind them the fishes. When we get back this far we are less certain but most probably the worms take up the story. So our ancestry runs back to the very beginning, when it originated in the one-celled animals which are also the ancestors of all the rest of the animal world. If we are inclined to deny our ancestors in the trees, what shall we say of our forefathers in the seas?

The question of course is not to be decided by our likes or our dislikes. If the evolution of man is true it will not make it less true because the process is not to our liking. It is our part, if this be the truth, to accept it as we do any other truth. Surely those of us who are moral of thought are not willing to disbelieve a truth because it is unpleasant.

The newness of the idea is the chief reason for our dislike of it. This lowliness of origin should not be distasteful to us. Nothing about Abraham Lincoln seems to us more wonderful than that a man who towered head and shoulders above his generation, indeed above most generations of men, in his fineness of life, in his nobility of purpose, in the integrity of his aims, should have been of exceedingly humble extraction. It only adds to the glory of his later achievements that he should have lived in a cabin, have spent his young manhood splitting rails and running a flat-boat, and have gained his education almost unaided from a few books and much meditation in front of a log fire.

That the greatest military General on the Union side of the Civil war should have been the son of a country tanner, and as a boy, not over-shrewd in the matter of bargains, adds to the glory of his later life. The simplicity of his childhood gives new luster to the power with which he led the forces of a nation to victory, and then went to a battle no less noble in his long fight for honor while suffering from disease and approaching death. Why then should we feel that such beginnings in the lower world are too humble for man? Why do we think his present superiority diminished by his lowly origin? Why can we not see that precisely the reverse is true? The more humble the level from which he sprang the more gloriously creditable is his present position. Instead of being ashamed of having risen from the brute, it should be the glory of man that he has so sprung. His chief superiority lies in the fact that while they have remained where they are, he has so completely outdistanced them as to have placed a gap between himself and them that seems almost impassable. Furthermore, if man with his present glory of intellect and of moral impulse, has sprung from a creature whose superiority to the ape lay chiefly in its potentialities, then it does not yet appear what he shall be. We can judge the future only by the past. Through the long ages the development has been very slow. Through the last hundred thousand years the development of man has been wonderfully rapid, compared with what went before, though it seems slow enough when we look at it from the standpoint of our historical and traditional reports. But with this added impulse, this rapid improvement that has come with the development of mind instead of muscle, of tooth and of claw, we have every promise of an evolution that shall far surpass anything that has yet come. To-day our leaders are way beyond the average of the mass. Who shall doubt that in a not too distant to-morrow, the masses shall be where the leaders of to-day now are. We shall not then have reached a dead level of superiority. Our leaders will have moved on as rapidly as have the masses, and will be as far ahead of them then as they are now. It shall be their work to apprehend new virtues, and to work them out in their lives. The masses, seeing the beauty of the lives of the leaders, recognizing in those lives the revelation of the divine power which they have apprehended, will hunger to learn of them and to lead lives like theirs. To this process who shall set an end? The advance is slow, as in all evolution; but anyone who wishes to do so may easily detect the direction of the current.

The evolution of man's physical frame probably has nearly ceased. Gradually organs that are useless to him are passing away. Slowly his hands are becoming more delicate and refined and skilled. But his evolution has begun to work itself out on entirely other lines. We sometimes hear that the men of the past were the full equivalent of the men of to-day. Scholars like to tell us that the population of Athens was finer in quality than any population that has existed since. We must remember that group after group of men may be expected to specialize intellectually and fail to develop morally and physically. Under these conditions this little branch of the human race runs through its forced flowering and comes to an end. With the study of history and the earnest investigation of these lives of the past, new possibilities arise within the human family. The next race that flowers may take longer to decay because it understands better the weaknesses that carried away the preceding civilization. In time there will arise a civilization that understands the past. A whole people will some time realize that intellectual development alone will not save it, or Athens would have lasted; that moral development alone will not suffice, or Judaea had been permanent; that physical development will not serve, or Sparta would stand to-day. Some day there will arise a nation that will see to it that every intellectual advance is accompanied by an equivalent moral and physical advance. When this time comes we shall have a race which can survive. Are we to be that race? The sins of man are generally the dregs of his brute ancestry. Bestiality of life was once common enough to attract no attention. Kings and nobles were not supposed to be clean so long as they confined their bestial relations to those below them in rank. Gradually men are becoming ashamed of uncleanness in life. Some day there will be no difference so far as purity of life is concerned, between the two who present themselves at the altar asking the blessing of God on their union.

If anyone doubts that English speaking people are becoming cleaner of life he needs only to consult the literature of the past. No one dreams of finding fault with Chaucer because his stories related in the company of men and women often would not bear such telling to-day. Shakespeare, with all his wonderful genius, needs expurgating if one would read him aloud comfortably to a mixed audience. And these are the shining stars. When we drop below them, the literature of their time becomes nearly impossible to read. Fielding and Smollett and Stern helped to build up the English novel, but the stories they tell speak of the grossness of their time in language that is unmistakable. We are by no means clean to-day. A fair proportion of our novels leave much to be desired. The stage is the scene of much we could wish to see cleaner. Above all this grossness there towers a sweetness and beauty of thought, and an earnestness of purpose, a sincerity of effort, which makes the present time fuller of moral purpose, fuller of the desire to be clean and to help others to be clean, than graced any previous period in the history of either England or America.

Under the change from country to city life man has suffered. Here too evolution is necessary. City life tells hard on the second generation and nearly destroys the third; but we have come to understand the difficulty and are fast remedying it. It is more than possible that the next generation will see such changes in the life of the worker in the great center, as shall effectively stop the physical deterioration that has come to the city dweller. God grant that modern civilization has had teaching enough and learned its lesson well enough. God grant further that we may give over slaughtering our most ambitious and vigorous young men in battle to settle questions which battle can never settle. God grant that we have come to a turning of the ways where the life of men, women and children, no matter how humble their station, shall stand higher in value than the profits of any commercial venture. God grant that we will soon be firm enough to declare that a business which can only live by sacrificing the health and strength of the workers must be counted an unprofitable business, and be allowed to cease. God grant finally that the American people may learn from the past to guard against a like fate in the future; that here may be the people whose strength, intelligence and uprightness shall lead the world; not for the sake of exceeding the world, but with the high mission of setting to the world an example of what can come to a vigorous, free and God-fearing people.

In the early history of the evolution of man the struggle almost always concerns the individual. Gradually the family comes to be the fuller unit. Only that is success which leads to the success of this higher group. After a time the family broadens to the tribe, and then the tribe to the nation. The evolution of social institutions is at present going on at an enormously rapid rate. Throughout the civilized world democracy is coming to its own. Even where the form of monarchy still prevails, the subjects of the monarch are having more and more rights. The people of England are surely as free as are the people of the United States. Increasingly all forms of government will secure for all their subjects, no matter what their station in life, a fair share of the general prosperity. In this field, human evolution is perhaps more rapid than in any other.

Any individual human being is a network of traits and peculiarities. He has all the ordinary attributes of humanity, but to the whole complex he gives an individual peculiarity which is totally his own. Where did he get his qualities? In the earlier times the fairies were supposed to have blessed him or cursed him in his cradle. A later age saw in the stars the rulers of man's destiny. He was jovial, or saturnine, or martial, depending on the planet which was in the ascendant at the time of his birth. Now we know "it is not in our stars but in ourselves that we are underlings." Everything a man is comes to him from within or from without; from nature or from nurture; from his heredity or from his environment. From our ancestors we get all the possibilities of our lives. To a certain extent we are slaves to our heredity, but not by any means to any such extent as to make us hopeless, unless our heredity is miserably bad. To the great mass of us come larger potentialities than we ever develop, and such possibilities of degradation as, fortunately, few of us ever reach. Within an enormously wide range, man is the architect of his own fortune. Only such traits develop as find a stimulus in the environment. Accordingly, a very large proportion of the development a man may achieve depends upon the circumstances under which he is placed, or, what is far more to the point, in which he may place himself. Man is not the blind sport of a relentless destiny. It is his to choose his environment; it is his to modify his environment when he cannot leave it. To an extent which no other animal has ever approached, man is the arbiter of his own destiny. A hypothetical ass may stand helpless between two equidistant bales of hay, but no human being is ever so helpless a sport of his environment. As it is, he may drift or he may rove as he pleases. To one man the current may be stronger than to another. There may be now and then a child so feeble-minded as to be unable to decide the course of its own life. It will not be long before society will see to it that such a life leaves behind it no strain cursed with its fatal weakness. In this effort to advance, man has all the advantage that comes from concentrated social effort. No man may live to himself. To every man in our community who desires it, a helping hand will be stretched. Often a hand will be stretched to him and he will be steadied whether he will or not, until his own will reforms itself and gains the mastery.

Inasmuch as all that is in man comes from his environment or from his heredity, the only way in which the race of men can be advanced is by improving their environment or by bettering their heredity. The first of these is the province of the sociologist; the second that of the eugenist. The sociologist has for some time been giving his careful attention to the improvement of the environment. In every large city, a man must build for himself a house fit to live in, if he build it at all. Whether he erects it for himself or for another makes no difference. Society will no longer allow him to build a home which is a detriment to the one who lives in it. Not only must he make himself a decent home but he must keep it in decent condition. The community will not allow him to endanger his own health, or that of his neighbor, by an insufficient method of attending to his garbage, or by a lack of ordinary cleanliness. If he will not clean his premises himself, the law sees to it that they are cleaned for him. Already we are beginning to understand that no man has a right to employ another man or woman or child at wages which are not sufficient to maintain the one thus employed. The wages of many people are exceedingly meager, notably those of women and children. He can read but ill the signs of the times who does not foresee an early end to the exploiting of the labor of these helpless creatures. Humanity has determined firmly that these things must pass, that the young child must not labor long or hard, that a woman must not be taxed beyond her strength. Already in England there is a partially successful movement which will doubtless spread to this country to provide that a woman be granted a little time before and after the birth of her child during which she shall not be allowed to suffer because her power to earn a wage is temporarily gone. These things cannot fail in the long run to strengthen the people. They strengthen chiefly the present generation. The blight of the fact that acquired characters cannot be transmitted, meets us here. This improved environment can only slowly, if at all, improve the race, and every effort made in this direction must be repeated with each generation.

Under such circumstances is it to be wondered at that the eugenist is hoping to raise the strain? Any improvement he can bring about is not only valuable for the generation in which it comes but is carried on into the generations which follow. This is the hope that strengthens and sustains him in his effort. The science of eugenics is so new, so little is surely known concerning the transmission of human characters, that no one is able as yet wisely to say what course is to be pursued in improving the race. But the problem is so interesting and its outcome so overwhelmingly important that men will never cease striving to know, and may, before many years, begin wisely to guide us in our efforts to provide a finer stock.

Heretofore our efforts at improving the strain have been confined to cattle, chickens and plants. An almost unalterable repugnance rises as soon as we speak of improving the human strain. Visions, if not stories, start up at once, of experimental matings of human beings, and of all other unspeakable abominations which no decent man expects to happen or even wishes to attempt. If there is one thing in human society the value of which has been demonstrated through the unending ages, it is the monogamic marriage. All ideal workers must point to the life-long union of a strong, vigorous, clean-minded and clean-lived man with a similarly fine, strong, clean-minded and clean-lived woman. Such an ideal may be slow in its attainment, but he aims too low who aims to secure anything less than this. The long struggle out of bestiality into pure monogamy has been so slow, so gradual, so noble in its attainments, and is still so far from perfection, that it would be an inconceivably stupid blunder to let go a single point that has been gained. Whether divorce shall be allowed to remedy a mistake may be a matter of dispute, but at best it is a bad remedy for a mistake that should never have been made. No ideal society could ever consider divorce as any permanent portion of its activities. Children are not like cattle. It is not simply a question of their being brought into the world sound and strong. Their long infancy which in the biological as well as in the legal sense, lasts until they are grown up, should be spent in surroundings which can minister, by example and precept, to moral and intellectual development. Surely no such end can possibly be attained when man and woman mate lightly, to part quickly.

At first sight it would seem a wise thing to require health certificates for those who would be married. I doubt not the Chicago Bishop who declined to marry his parishioners except under such conditions, will exert a beneficial effect upon the country by the attention he thus attracts to the subject. It would be a bad day for the city if all the clergy and all the other authorities who are authorized to solemnize marriage should take this step. We have not yet arrived at such a stage of development that a marriage certificate is essential to mating, and a restriction of this sort would simply mean that there could be no legitimate union except of those in strong health. To the burden of ill health would be added the still worse handicap of an illegitimate parentage, with all its bitter train of scorn and shame. Accordingly, it must be possible before the law for those who are not thoroughly vigorous to marry. But, year by year, we may come nearer accomplishing a finer mating by the aims and purposes we foster in the growing generation. Marriages will never be worth while when they are not freely entered into by the contracting parties. Choice must be free and unrestricted if it is to last for life; but this does not mean that it must be unguarded. It would be bitter folly for parents to leave to their children, without attempt to influence or restrain, the making of their marriages. The mating of our children must be inspired, not directed.

There is one taint from which society has the right and the duty of freeing itself, so far as in its power lies. This is the taint of feeble-mindedness. Of all the calamities that can befall a human being, feeble-mindedness is, perhaps, the worst. From most misfortunes it is possible to recover; with most of the rest one may exist without detriment to the race. To be feeble-minded simply means to hark back to the level of our animal ancestors, without regaining their power to guide life. The animal is provided with a bundle of instincts which tell him what to do in all the ordinary emergencies of life. The human species, in its development, has lost a large portion of its instincts, and has gained, instead, the power of intelligent choice and the ability to learn by imitation. When these drop away, man without his instincts or his intelligence is more helpless than the brute. Students of sociology are making clear to us that a large portion of the criminality of the world, much of the looseness of life, and a large part of the alcoholic excesses are due to this taint of feeble-mindedness. Recent investigations have made it clear that one feeble-minded family in a community may, in the course of years, poison the life of an entire state. The Jukes family in New York, the Kallikak family in New Jersey, have shown the awful possibilities of descent from a single feeble-minded ancestor. Prisons, almshouses, and houses of shame owe their population in no small degree to this bitter curse. It will not be long before society will learn to protect itself against such poisoning of the human stock. Nothing is more clear to the investigator of this subject than that the one overwhelming cause for feeble-mindedness is feeble-mindedness in the parentage.

There is one type of mental weakling, known as the Mongolian idiot, which may arise right out of the heart of an apparently sound family. But the number of these is comparatively small. The number of feeble-minded, who are feeble-minded because of their heredity, is dishearteningly and astonishingly large. Every attempt to examine large numbers of school children shows a sickening proportion of those who are distinctly feeble. Every little community seems to have its boy or girl who is what is known as silly. Such people rarely live long lives without leaving behind them feeble-minded children, no small proportion of whom are likely to be illegitimate. Against this fouling of the stream at its source, society must protect itself. Legislators revolt at the somewhat inhuman but certainly safe method of surgically preventing the possibility of the feeble-minded becoming parents. It would be more creditable and just as effective if society would take upon itself the tremendously expensive task of caring for all its feeble-minded in institutions during their entire life. The cost would be large for a generation, but would rapidly diminish and eventually become small. It certainly would be the humane way. These people in good institutions are by no means unhappy. Within the limit of their capacities they can do many things. Wise management usually will secure from them labor enough of wholesome and simple kind nearly to pay for their own support. Nothing could be better for them than to till the soil, care for the cattle, tend the chickens, and, in this way, provide very largely the materials on which they are fed. How this problem shall work out, time only can decide. With it once worked out, there is no doubt that the level of humanity will be distinctly raised. No other one feature in the program of eugenics seems more absolutely hopeful than this.

In several of the states of the Union it has recently become the practice to remove the possibilities of parenthood from certain classes of criminals. The purpose of this is clear and benevolent. Society has a right to prevent the oncoming of new generations of foreordained criminals. Underlying the practice is the theory that the children of criminals are born criminals. It is far from likely that this is the case. Criminality may be due to a wide range of causes. If the criminal is one of those actual born degenerates whose whole mental and physical make-up is so defective that nothing but criminality can be expected of him, then we have a case in which it is clear that society may, and should, remove the possibility of having more generations of the same kind. Probably only a moderate proportion of the criminals in our jails and penitentiaries belong to this class. Doubtless a distinct majority are criminals more through environment than through heredity. Born of average ability, or more, these people have been criminals simply because they were reared among criminals, because their surroundings were such as to lead them away from habits of industry, while they must live. These people were not bolstered by society, or the church, into a life of self-respect and self-help. Under these circumstances they fell into evil ways. There is nothing defective in their mental or physical make-up, that need appear in their children. If these children are removed from contact with the criminal class they stand every chance of being as vigorous, as intelligent, as upright as the average of the community.

At the recent Eugenics Congress in London one of the speakers expressed a preference for the son of a husky burglar over the son of a tuberculous bishop. This is doubtless quite correct, but why should the bishop be tuberculous? The truth of the matter is, the reverse is more likely to be the case. Personally, I should prefer to be the offspring of a husky bishop. In dealing with criminals, then, with a view to cutting off their posterity, we must be careful to understand whether we are dealing with a hereditary or an acquired criminality. If there is a genuine hereditary criminal taint, society is right in freeing itself of it. If it is acquired criminality, then it is not transmissible, and the offspring, if placed in a good environment, are likely to be good citizens. All of which means that, until we are clearly sure of what constitutes a hereditary criminal trait, we should move very slowly in the matter of mutilating criminals.

What steps may the eugenist, with his present limited knowledge, clearly, hopefully and confidently take to improve the future of the human species? There is one avenue open to us in this matter in which we can hardly go wrong. Even our mistakes can work little harm, and every well-done piece of work in this field will be a blessing to the race. This step lies in inculcating in our boys and girls high ideals of parenthood. This is more effective than legal prohibition of certain forms of marriage which cannot prevent matings, and adds the curse of illegitimacy to the other handicaps of the children of such unions. The first step in this process has already been reasonably well accomplished. Both our boys and our girls are in love with health. A good husband and a good wife should be healthy and vigorous. This does not mean that we expect a boy or girl who is looking forward to marriage to sit down and ask himself deliberately about the health of the person with whom he would mate. We must fill our children with the love of outdoor life, with the love of exercise. This will foster in them an admiration for people who are vigorous of body and alert of mind. It ought to become practically impossible for a hearty and vigorous boy to fall in love with a helpless and anaemic girl. It should be equally impossible for a hale and active girl to admire a man who was her inferior in either vigor or alertness. The modern taste for outdoor life has largely brought this to pass among such of our people as have leisure enough to indulge in vigorous sport. Among the crowded dwellers in the closer sections of the city such life has been so nearly impossible that no ideal of vigorous manhood or of radiant womanhood has had a chance to grow up. With the oncoming of the parks and play-grounds, all of this, we may hope, will change. Health and vigor will be no less attainable and hence no less adorable in the city than in the country. Rich and poor alike will be attracted by rosy cheeks and an elastic gait.

Our aim, however, should not cease with a vigorous body. We must teach our young men and young women the glory of a well disciplined mind. This should seem quite as admirable to them as a vigorous body. To them, straight thought ought to be as lovable as a firm and supple body. In this matter our young people are less exacting. The ordinary conversation of people gathered together for social purposes is not particularly intellectual, and any attempt to make it so at present seems priggish. With a broader education, will come keener demand for intelligence. We may hope the time is not too far distant when a question of governmental policy, a new book or play, or a new discovery in science will stimulate as much conversational zest as now seems to be gotten from a pack of cards.

A third feature of the ideals which should be instilled into the minds of our children is the moral phase. There seems little doubt that this is on the way. We must not mistake an evident laxness of religious observance as being synonomous with moral looseness. The revelations which our recent periodicals have brought us concerning the habits of business men, of politicians, and of society, have left on many minds the impression that this is distinctly an age of decadence. Exactly the reverse is the truth. This is the age of intense sensitiveness to wrong. In almost no particular is it worse than any previous age in the history of our country. We openly discuss things which we left untouched a little while ago. We insistently demand that business practices to which nobody particularly objected a dozen years ago must now certainly cease. All of this has produced an erroneous impression that the times are out of joint. But the dust and dirt in the air is the unavoidable accompaniment of house cleaning. When doubtful practices simply have publicity many are awakened to the sense of their duty to society. Persons who, of themselves, might be willing to live low and godless lives, dare not do so in the face of society when our social ideals are finer. I believe there is the utmost hope that within two generations our young men and young women will scorn meannesses which we are accepting with entire complacency.