It is hardly necessary to insist on the certainty that our present imperfect knowledge of the limitations and conditions of hereditary transmission will be steadily added to; but I would call attention again to the serious want of adequate materials for study in the form of life-histories. It is fortunately the case that many of the rising medical practitioners of the foremost rank are become strongly impressed with the necessity of possessing them, not only for the better knowledge of the theory of disease, but for the personal advantage of their patients, whom they now have to treat less appropriately than they otherwise would, through ignorance of their hereditary tendencies and of their illnesses in past years, the medical details of which are rarely remembered by the patient, even if he ever knew them. With the help of so powerful a personal motive for keeping life-histories, and of so influential a body as the medical profession to advocate its being done,[21] and to show how to do it, there is considerable hope that the want of materials to which I have alluded will gradually be supplied. [Footnote 21: See an address on the Collective Investigation of Disease, by Sir William Gull, _British Medical Journal_, January 27, 1883, p. 143; also the following address by Sir James Paget, p. 144.] To sum up in a few words. The chief result of these Inquiries has been to elicit the religious significance of the doctrine of evolution. It suggests an alteration in our mental attitude, and imposes a new moral duty. The new mental attitude is one of a greater sense of moral freedom, responsibility, and opportunity; the new duty which is supposed to be exercised concurrently with, and not in opposition to the old ones upon which the social fabric depends, is an endeavour to further evolution, especially that of the human race. APPENDIX A.--COMPOSITE PORTRAITURE. The object and methods of Composite Portraiture will be best explained by the following extracts from memoirs describing its successive stages, published in 1878, 1879, and 1881 respectively:-- I. COMPOSITE PORTRAITS, MADE BY COMBINING THOSE OF MANY DIFFERENT PERSONS INTO A SINGLE RESULTANT FIGURE. [_Extract from Memoir read before the Anthropological Institute, in 1878_.] I submit to the Anthropological Institute my first results in carrying out a process that I suggested last August [1877] in my presidential address to the Anthropological Subsection of the British Association at Plymouth, in the following words:--