An incalculable amount of lower life has been certainly passed through before that human organisation was attained, of which we and our generation are for the time the holders and transmitters. This is no mean heritage, and I think it should be considered as a sacred trust, for, together with man, intelligence of a sufficiently high order to produce great results appears, so far as we can infer from the varied records of the prehistoric past, to have first dawned upon the tenantry of the earth. Man has already shown his large power in the modifications he has made on the surface of the globe, and in the distribution of plants and animals. He has cleared such vast regions of forest that his work that way in North America alone, during the past half century, would be visable to an observer as far off as the moon. He has dug and drained; he has exterminated plants and animals that were mischievous to him; he has domesticated those that serve his purpose, and transplanted them to great distances from their native places. Now that this new animal man, finds himself somehow in existence, endowed with a little power and intelligence, he ought, I submit, to awake to a fuller knowledge of his relatively great position, and begin to assume a deliberate part in furthering the great work of evolution. He may infer the course it is bound to pursue, from his observation of that which it has already followed, and he might devote his modicum of power, intelligence, and kindly feeling to render its future progress less slow and painful. Man has already furthered evolution very considerably, half unconsciously, and for his own personal advantages, but he has not yet risen to the conviction that it is his religious duty to do so deliberately and systematically.
The fact of an individual being naturally gifted with high qualities, may be due either to his being an exceptionally good specimen of a poor race, or an average specimen of a high one. The difference of origin would betray itself in his descendants; they would revert towards the typical centre of their race, deteriorating in the first case but not in the second. The two cases, though theoretically distinct, are confused in reality, owing to the frequency with which exceptional personal qualities connote the departure of the entire nature of the individual from his ancestral type, and the formation of a new strain having its own typical centre. It is hardly necessary to add that it is in this indirect way that natural selection improves a race. The two events of selection and difference of race ought, however, to be carefully distinguished in broad practical considerations, while the frequency of their concurrence is borne in mind and allowed for.