conscious and reflect on its own existence?

We cannot

answer; nor can we answer in regard to the ascending organic scale. The half-art and half-instinct of language still bears the stamp of its gradual evolution. The ennobling belief in God is not universal with man; and the belief in active spiritual agencies naturally follows from his other mental powers. The moral sense perhaps affords the best and highest distinction between man and the lower animals; but I need not say anything on this head, as I have so lately endeavoured to shew that the social instincts,-the prime principle of man's moral constitution 39-with the aid of active intellectual powers and the effects of habit, naturally lead to the golden rule, " As ye would that men should "do to you, do ye to them likewise;" and this lies at the foundation of morality.

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In a future chapter I shall make some few remarks on the probable steps and means by which the several mental and moral faculties of man have been gradually evolved. That this at least is possible ought not to be denied, when we daily see their development in every infant; and when we may trace a perfect gradation from the mind of an utter idiot, lower than that of the lowest animal, to the mind of a Newton.

39

'The Thoughts of Marcus Aurelius,' &c., p. 139.

CHAPTER IV.

ON THE MANNER OF DEVELOPMENT OF MAN FROM SOME

LOWER FORM.

Variability of body and mind in man- Inheritance - Causes of variability Laws of variation the same in man as in the lower animals Direct action of the conditions of life- Effects of the increased use and disuse of parts-Arrested development - Reversion Correlated variation - -Rate of increase - Checks to increase Natural selection-Man the most dominant animal in the world-Importance of his corporeal structure - The causes which have led to his becoming erect-Consequent changes of structure Decrease in size of the canine teeth-Increased size and altered shape of the skull — Nakedness - Absence of a tail-Defenceless condition of man. We have seen in the first chapter that the homological structure of man, his embryological development and the rudiments which he still retains, all declare in the plainest manner that he is descended from some lower form. The possession of exalted mental powers is no insuperable objection to this conclusion. In order that an ape-like creature should have been transformed into man, it is necessary that this early form, as well as many successive links, should all have varied in mind and body. It is impossible to obtain direct evidence on this head; but if it can be shewn that man now varies -that his variations are induced by the same general causes, and obey the same general laws, as in the case of the lower animals-there can be little doubt that the preceding intermediate links varied in a like manner. The variations at each successive stage of descent must, also, have been in some manner accumulated and fixed.

The facts and conclusions to be given in this chapter relate almost exclusively to the probable means by which the transformation of man has been effected, as far as his bodily structure is concerned. The following chapter will be devoted to the development of his intellectual and moral faculties. But the present discussion likewise bears on the origin of the different races or species of mankind, whichever term may be preferred.

It is manifest that man is now subject to much variability. No two individuals of the same race are quite alike. We may compare millions of faces, and each will be distinct. There is an equally great amount of diversity in the proportions and dimensions of the various parts of the body; the length of the legs being one of the most variable points. Although in some quarters of the world an elongated skull, and in other quarters a short skull prevails, yet there is great diversity of shape even within the limits of the same race, as with the aborigines of America and South Australia, the latter a race "probably as pure and "homogeneous in blood, customs, and language as any "in existence "—and even with the inhabitants of so confined an area as the Sandwich Islands.2 An eminent dentist assures me that there is nearly as much diversity in the teeth, as in the features. The chief arteries so frequently run in abnormal courses, that it has been found useful for surgical purposes to calculate

1 'Investigations in Military and Anthropolog. Statistics of American Soldiers,' by B. A. Gould, 1869, p. 256.

2 With respect to the "Cranial forms of the American aborigines," see Dr. Aitken Meigs in Proc. Acad. Nat. Sci.' Philadelphia, May, 1866. On the Australians, see Huxley, in Lyell's Antiquity of Man,' 1863, p. 87. On the Sandwich Islanders, Prof. J. Wyman, 'Observations on Crania,' Boston, 1868, p. 18.

4

5

from 12,000 corpses how often each course prevails." The muscles are eminently variable: thus those of the foot were found by Prof. Turner not to be strictly alike in any two out of fifty bodies; and in some the deviations were considerable. Prof. Turner adds that the power of performing the appropriate movements must have been modified in accordance with the several deviations. Mr. J. Wood has recorded the occurrence of 295 muscular variations in thirty-six subjects, and in another set of the same number no less than 558 variations, reckoning both sides of the body as one. In the last set, not one body out of the thirty-six was "found totally wanting in departures from the standard descriptions of the muscular system given in anatomical "text-books." A single body presented the extraordinary number of twenty-five distinct abnormalities. The same muscle sometimes varies in many ways: thus Prof. Macalister describes no less than twenty distinct variations in the palmaris accessorius.

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The famous old anatomist, Wolff," insists that the internal viscera are more variable than the external parts: Nulla particula est quæ non aliter et aliter in aliis se habeat hominibus. He has even written a treatise on the choice of typical examples of the viscera for representation. A discussion on the beau-ideal of the liver, lungs, kidneys, &c., as of the human face divine, sounds strange in our ears.

The variability or diversity of the mental faculties in men of the same race, not to mention the greater

3' Anatomy of the Arteries,' by R. Quain.

4 Transact. Royal Soc.' Edinburgh, vol. xxiv. p. 175, 189.

5 Proc. Royal Soc.' 1867, p. 544; also 1868, p. 483, 524. There is

a previous paper, 1866, p. 229.

6 Proc. R. Irish Academy,' vol. x. 1868, p. 141.

'Act. Acad.,' St. Petersburg, 1778, part ii. p. 217.

differences between the men of distinct races, is so notorious that not a word need here be said. So it is with the lower animals, as has been illustrated by a few examples in the last chapter. All who have had charge of menageries admit this fact, and we see it plainly in our dogs and other domestic animals. Brehm especially insists that each individual monkey of those which he kept under confinement in Africa had its own peculiar disposition and temper: he mentions one baboon remarkable for its high intelligence; and the keepers in the Zoological Gardens pointed out to me a monkey, belonging to the New World division, equally remarkable for intelligence. Rengger, also, insists on the diversity in the various mental characters of the monkeys of the same species which he kept in Paraguay; and this diversity, as he adds, is partly innate, and partly the result of the manner in which they have been treated or educated.8

9

I have elsewhere so fully discussed the subject of Inheritance that I need here add hardly anything. A greater number of facts have been collected with respect to the transmission of the most trifling, as well as of the most important characters in man than in any of the lower animals; though the facts are copious enough with respect to the latter. So in regard to mental qualities, their transmission is manifest in our dogs, horses, and other domestic animals. Besides special tastes and habits, general intelligence, courage, bad and good temper, &c., are certainly transmitted. With man we see similar facts in almost every family; and we

6

8 Brehm, 'Thierleben,' B. i. s. 58, 87. Rengger, Säugethieré von Paraguay,' s. 57.

9 Variation of Animals and Plants under Domestication,' vol. ii. chap. xii.