offspring; in other words, science does not, as a body, accept the theory that the effects of use and disuse in the parent are inherited by his children. Modern science does not, indeed, definitely foreclose discussion of the subject, but what it says is that the empirical issue is doubtful with a considerable balance against the supposed inheritance of acquired characters.

Very recently evidence has, indeed, been adduced to prove that "Initiative in animal evolution comes by stimulation, excitation and response in new conditions, and is followed

by repetition of these phenomena until they result in structural modifications, transmitted and directed by selection and the law of genetics." The student who tenders this evidence is Dr. Walter Kidd[12] who claims that his observations of the growth of the hair of the harness-horse prove that the prolonged friction caused by the harness produces heritable effects in the pattern of the hairy coat of this animal. It is admitted by this observer that such momentary and acute stimuli as are involved in the mutilation of the human body by boring holes in the ears, knocking out teeth, and by circumcision, which practices have been followed by so-called savages during long ages, seldom, if ever, lead to inherited characters, but he maintains that the effect of prolonged friction by the collar on the hair on the under side of the neck of the harness-horse has produced marks or patterns in the same place on certain young foals born by these horses.

These observations must, of course, be submitted to strict examination before science

will pronounce its opinion. Meanwhile I may be allowed to cite what Dr. Kidd calls an "undesigned experiment," which to my mind goes far to prove that the effects of prolonged friction on the human body during many generations is not heritable. The custom followed by many Bantu tribes of producing in their women an elongation of the genital parts by constant manipulation must have been practiced during very many generations, certainly much longer than the comparatively recent harnessing of horses in England, for we know how tenaciously primitive people cling to their old customs, generation after generation, for thousands of years, and yet no instance has ever been noticed by these people, who are very observant in these matters, of any sign of such an inherited characteristic in any of their female children.

The ordinary layman, though he may feel strongly interested in the problems of heredity and evolution, has seldom the leisure or the opportunity for the careful study of biological data, and he must therefore leave these to the specialists in scientific enquiry, but he is by no means precluded from

using his own common-sense in drawing conclusions from the ordinary plain facts of life observable around him. It is when we come to consider this most important question in its bearing upon the mental side of the human being that the ordinary layman feels himself to be no less competent to form an opinion than the trained man of science.

Is it possible, then, we ask, for the parent whose intellect has been developed through training in his lifetime to transmit to his children any portion of this acquired increment of mental capacity, or, putting the question in more concrete terms, is it possible for a parent to transmit to his offspring any part of that power to increase the size and quality of the brain which may be assumed to have resulted in his own case from mental exercise? The question must not be misunderstood. We do not ask whether clever parents do as a rule have clever children; what we want to know is whether the successive sharpening of the wits of generations of people does, or does not, eventually result in establishing a real and cumulative asset of mental capacity.

Seeing that universal education has only come about within the latter part of the last

century it must be clear that the vast majority of the present generation of educated Europeans are descended from people who never had any of that education which so many people nowadays regard as essential to the development and growth of the intellectual powers. But although education has only recently become, in various degrees, common to all white people, the light of learning has always been kept burning, however dimly at times, in certain places and circles, and it may, perhaps, be possible to find people to-day who are the descendants of those favoured few who have enjoyed, during many unbroken generations, the privilege of liberal education. Now let us assume that there are at present a small number of such people in the forefront of the intellectual activity of the day, and then let us ask ourselves whether these leaders of thought who can claim long lineal descent from learned ancestors show any mental capacity over and above that which is displayed by those commoners who are also in the foremost ranks of thought and science, but who cannot lay claim to such continuous ancestral training.

If we admit the existence of two such separate classes to-day then the answer must surely be that there is no mental difference discernible between them. But I think we may safely conclude that there has been very little of the kind of descent here presumed. It would be well-nigh impossible to find people who could prove an unbroken lineage of educated forbears going back more than four hundred years. During the middle ages the monks of the Church were the chief and almost sole depositories of education and learning, and as they were bound by their vows to life-long celibacy there could be no transmission from them to posterity of any of that increased capacity of brain which we are supposing as having been acquired by each individual through his own mental exertion. We know, of course, that there were frequent lapses from the unnatural restraint imposed on these men so that some of them may have propagated their kind, but such illegitimate offspring was not likely to remain within the circle of learning and therefore could not perpetuate the line. We of to-day know full well that the son of the common labourer whose forefathers had

no education can, with equality of opportunity, achieve as much and travel as far in any field of mental activity as can the scion of the oldest of our most favoured families.

There does not seem to have been any augmentation of human brain power since written records of events were begun. Indeed it would seem rather as if there had been in many places a decrease in intellectual capacity, as when we compare the fellahin of modern Egypt with their great ancestors whom they resemble so closely in physical appearance that there can be little doubt about the purity of their descent. The same may be said about the modern descendants of the people who created "the glory that was Greece and the grandeur that was Rome." And when we consider the period of the Renaissance we cannot say that civilised man of to-day is superior to those people who after centuries of stagnation and general illiteracy were yet able to seize and develop the long-forgotten wisdom and philosophy of antiquity.

To go still further back and to venture beyond the historical horizon into the dim past when prehistoric man roamed over

Europe is a task manifestly beyond the powers of the ordinary layman, and here we must, perforce, trust ourselves to the guidance of those students whose training and special learning entitle them to speak with authority.

The so-called Piltdown skull which was discovered in 1912 is accepted as representing the most ancient of human remains yet found in England, its age being estimated at somewhere between 250,000 and 500,000 years. In discussing the size and arrangement of the lobes and convolutions of the brain which this cranium must