strange question of the permanence and domination of races in various regions of the earth which the facts of colonization are bringing into view at the present day. We have before given reasons for not looking for permanency of peculiarities in such characters as longevity in the races of mankind. Sir Charles Dilke, in his admirable sketch 'Greater Britain,' notes the disappearance of the Anglo-Saxon element and character in the Eastern United States, not only by the influx of Irish and German elements (both of which races are reputed shorter lived than the Anglo-Saxon), but by a direct influence of the locality-an unfitness of the soil to the plant-which involves either the death or the modification of the latter. Moreover, the immigration of short-lived and unhealthy classes, and the extraordinary intensity of life, implying rapid expenditure-which has become a thoroughly American characteristic, whether from climatic or social influences, or both-must greatly diminish American longevity. To use their own expressive phrase, they are a 'go-a-head' people, and the early ageing of both male and female inhabitants of the States is an example of an individual tendency to travel fast as regards age, which is strictly dependent on, or correlated with, their activity. It is not unlikely that the small longevity of Americans—if it be a real phenomenon is a transient attribute of the population, which, with other characteristics, will be

greatly changed for what is happier and better in the future consolidation and development of that great people.

19. Duration of Life in past Time.

Under this heading, there is little more to be said than was contained in a celebrated but brief chapter. 'There is nothing known' of the duration of life in past time. A few years since it was the belief, based upon supposed statistical facts, that the potential longevity of man, that is, the expectation of life in the higher ages, was increasing and had been increasing for a hundred years. Dr. Farr has fully exposed the fallacy involved in this supposition, which was due to life-tables, erroneously constructed by Dr. Price (to whom, nevertheless, credit is due as a vital statistician), from the mortuary records of the town of Northampton. Dr. Farr has shewn that a table constructed by Price's method gives the same results to-day for Northampton as it did in the celebrated doctor's time. Moreover, the statistics of Sweden, which are very ample, extend from the middle of the eighteenth century, and furnish no indication whatever of a change. Some few facts have been adduced by Dr. Guy, which tend to shew a slight fluctuation in longevity in past centuries (see Tables K), but are really too few in number to allow of any generalization by even the most venturesome.

There is not within the cognizance of the writer a single fact of any antiquity to help us materially in the enquiry, unless it be thought that the limitation. of life to seventy or eighty years in the Psalms is a smaller span than such a writer would now assign; but this supposition is not worth further consideration.

It is very well ascertained that average longevity has immensely increased since the middle ages in Europe; the question, however, of mortality clearly does not come within the limits of this Essay. It would be very satisfactory could some general relation between high average longevity and high potential longevity among men-i. e. small deathrate at early and late ages-be established, but the facts are conflicting, and deductive analysis renders it improbable that any constant relation does obtain, as was pointed out in treating of longevity in organisms generally.

20. The Influence of various States of Civilization.

We have seen that the influence of civilization cannot be fairly examined inductively, but the facts quoted, and the conclusions they offer, warrant us in supposing that a civilization of the highest order, in which the efficiency of the community and the efficiency of the component individuals is greatest-in which there is the most harmonious action, the greatest happiness for the greatest number, the least

excessive expenditure with the least luxury, where regularity and temperateness are innate characteristics, will be that state of civilization most favourable to longevity. It may be supposed by some that since the tendency of civilization at present is to call out increased mental expenditure, that even when the other conditions of longevity are complied with, future men will rather lose than gain in longevity. This, however, depends upon the assumption, which we have no ground for allowing, that the structural capacity for such requirements will not increase simultaneously. There is every reason to believe that it will-that it is so doing. We are now in the midst of a struggle-in a transition state—which is really causing a survival of the fittest, operating chiefly through the emulation of communities, but also on individuals, and by means of this struggle greater mental power is being added to the human race. As we had occasion to remark in the case of organisms generally (quoting Mr. Herbert Spencer), increased difficulty of life-conditions necessitates increased evolution, and this is true for man's mental progress as for general structural progress. Were the evolution not always in advance of the provoking cause, we might anticipate the extinction of humanity by the excessive competition and excessive difficulties of existence which must accompany increased population. More justly, as it appears, and more hopefully, we may look forward to a time when, the

whole earth being peopled, man will become finally adjusted to his conditions by the limitation of his expansion and the closer interaction of the members of the human aggregate. In that almost perfect civilization-where the greatest happiness for every individual must finally be attained-will man's longevity be extended? It does not seem improbable that this may be the case: and certainly an average longevity coincident with the potential is, under those conditions, to be looked for. Men would no longer 'die of disappointment,"1 but would all attain eighty or a hundred years. There is no apparent reason why longevity should not increase beyond that limit, and advance with advanced evolution, and the diminished expenditure implied in more complete adjustment.2

1 Buffon.

2 It has been asserted by a writer in Fraser's Magazine' (September, 1869), and endorsed by another writer in the 'Spectator,' that civilization acts so as to suspend Darwin's law in the case of man—the feeble and diseased being allowed to breed, and the inferior often inheriting wealth won by no merit of their own, which could not be the case were there a free struggle for life and consorts. This is supposed to tend to shorten the life of the species, and to produce general inferiority in civilized races. But the argument is based on fallacy. As we have pointed out, man is a social animal, and the social virtues, which are urged by some persons as causes of deterioration, are the very strength of the communities in which they have been naturally and necessarily developed. That 'the individual withers, and the world is more and more,' as sung by Tennyson, is profoundly true. Natural selection operates largely on communities of men in place of individuals. That the fitter do survive, even in the case of individuals, is, however, clear enough. The diseased and feeble who propagate produce some healthy children, and these surely and certainly