laws of heredity in so far as relevant; and men of science now hold that changes in our surroundings to-day will affect the inborn qualities of succeeding generations either not at all-this being the belief of the majorityor only after the lapse of a very long period of time. The eugenist must not rely on the inheritance of acquired differences as an adequate foundation on which to base his projects of reform.

CHAPTER VIII

NATURAL SELECTION

Of all the possible methods of promoting racial progress, selection now alone remains to be considered, all the others having been ruled out as being either too slow or too uncertain in their action, or because the reforms thus indicated as being beneficial can be more effectively advocated on grounds other than eugenic. In considering whether any method of selecting the better types for multiplication, or the worse types for elimination, can form a practical basis for eugenic reform, those eugenists who, like myself, are hoping to be able to utilize the methods which have been effective in organic evolution, are inevitably led to consider what guidance can be obtained from a study of the action of natural selection. So much has been written during the last half-century concerning this subject that there is no excuse now for any mistake being made as to the meaning of the term 'natural selection'; and yet evidently it is still constantly misunderstood. Those who, being aware of their own ignorance, really wish to form an independent judgment in regard to the part which has been played by natural selection in the evolution of existing organisms must look elsewhere for information; for here all that will be attempted will be to give a brief reminder of the broad issues involved in the controversies which have raged on this subject. It is hoped that sufficient will, however, here be said to show that the study in nature of the action of natural selection, whilst giving valuable indications of what may possibly be accomplished in regard to mankind by means of eugenic reforms, yet teaches us hardly anything as to the exact methods by means of which we

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ought to endeavour to improve the inborn qualities of future generations.

The belief in natural selection as an evolutionary agency is founded on three indisputable facts. The first of these is that organisms always reproduce their kind with what may be described as unnecessary rapidity. During the past history of the world, the number of individuals belonging to any one species of animals must have remained approximately stationary for long periods of time; and, when this was the case, the disappearance of each couple, consisting of a male and a female, must always have been made good by the appearance of one other couple, no more and no less. In other words, normally every animal who became a parent on the average produced exactly two offspring, one male and one female, who themselves lived to become parents. But we know that animals of all kinds produce during their lives, as a rule, far more than two offspring; and from this it follows that the excess of offspring above two produced by each pair of animals must normally and on the average have been eliminated somehow or other from amongst those destined to become parents. And this inevitable elimination is known as the struggle for existence, the word 'struggle' here being used somewhat metaphorically; for the elimination has often been brought about by methods not involving any actual striving or contest. At a time when the number of individuals belonging to any one species was increasing, the number of those individuals in any one family destined to become parents was no doubt on the average somewhat over two; but we can confidently state that numbers never increased nearly as rapidly as would have been the case if all those who were born had become parents, and consequently that large numbers of organisms were somehow or other in the struggle for existence always being prevented from becoming parents.

The second indisputable fact on which a belief in natural selection is based, is that it is the least fit who leave fewest progeny behind them. If we define the fit as those so endowed by nature as to enable them most certainly to survive and multiply in the environment in which they

find themselves, then this statement, as we shall see, becomes very nearly a truism; provided that it be admitted that more are always born into the world than can possibly play a part in the production of the succeeding generation. In any case, it must never be forgotten that the word 'fit,' when used in connexion with evolutionary problems, implies no ethical superiority whatever. As to the ways in which the more fit have always been selected so as to give them a preferential chance of becoming the ancestors of the succeeding generations, they are so numerous that only a few of them can here be mentioned. All kinds of animals have to encounter periodic or occasional seasons when the available food supply is inadequate for their needs, the tough surviving at such times, whilst the naturally feeble die off in great numbers. In comparison with the more fit, those poorly endowed by nature in regard to agility, strength, size or cunning are always handicapped in their search for food, with some decrease in their chances of survival. The incidence of disease falls most heavily on those naturally susceptible to various ailments. Again, natural selection acts by killing off the offspring of parents exceptionally deficient in those natural instincts which induce them to protect their young. Lastly, such animals as are least capable of attracting or winning a mate will be those who oftenest fail in the struggle for existence in the broad sense in which that term is here used. These are but samples of the many ways in which nature has always favoured the more fit individuals or tribes when necessarily keeping down the numbers of individuals of each species to its normal level.

In passing it may here be worth noting that if in scientific discussions the survival of the fittest means little more than the survival of those who do in fact survive, yet when we come to discuss eugenic reforms, we are apt to attach a somewhat different meaning to the word 'fittest.' The aim of eugenists is to alter human surroundings in such a way as to increase the chance of survival' of those types which are held to be most desirable; and consequently in eugenic discussions the fittest' is a term sometimes

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used to indicate those who ought to survive' in the evolutionary sense-that is to help to people the earthrather than those who actually do survive. Natural selection seems to take no thought as to what is good,' whilst in eugenic problems the moral qualities of man should be the primary consideration.

The third of the basic facts on which a belief in natural selection is founded is the fact of heredity-that like tends to produce like, the qualities of parents always in a measure reappearing in their offspring. If those who succeed in the struggle for existence do so because they are above the average in any useful natural quality, such as cunning, strength, agility, freedom from disease, capacity for guarding their young, attractiveness to the other sex, etc., their offspring will also normally be above the average in this same useful quality. In this way natural selection has always been slowly relatively increasing the numbers of those types which possessed any inborn qualities giving them superior powers of survival or multiplication or, in other words, who were more fit for the particular environments in which they were placed. In so far as evolution has been brought about by natural selection, this is the way in which that agency has acted.

It may perhaps here be urged that selection in nature is often like a lottery, in which the unfit are just as likely as the fit to draw a prize. For example, out of the thousands of seeds which fall on the ground to perish, the single seed which lights on a suitable vacant spot, and which, therefore, survives to form another tree, seems to have been selected from the rest by blind chance. No doubt the causes which result in the selection of a particular organism for survival are often unconnected with its natural qualities, and natural selection is in this sense often largely fortuitous. The selection of the organisms which will survive to form a new generation is, however, never an entirely haphazard process, dependent only on pure luck in the matter of environment. There are always more seeds falling on good ground than can survive, and a seed if'selected' to carry on the race will always