of opportunity, education and social reform would be of no significance. Such an extreme position, though it is approached by men with so much authority as Sir Francis Galton, Professor Karl Pearson, Dr. R A. Woods, Dr. C. B. Davenport and Professor E. L. Thorndike, is untenable. Equally extreme in the opposite direction is M. Odin's aphorism "Genius is in things not in men," or the not uncommon opinion that almost anything can be done with a child by training and education. It is a problem of degree and of circumstance, a scientific question that could probably be solved within a reasonable time, if as much intelligence and money were devoted to it as to one of the bureaus of the Department of Agriculture.
In the meanwhile we must do the best we can with the material at hand, even though the interpretation is in nearly all cases ambiguous. It is here shown that 43 per cent, of our leading scientific men have come from the professional classes. We may conclude that more than one half of our men of science come from the one per cent, of the population most favorably situated to produce them. The son of a successful professional man is fifty times as likely to become a leading scientific man as a boy taken at random from the community. My data also show that a boy born in Massachusetts or Connecticut has been fifty times as likely to become a scientific man as a boy born along the southeastern seaboard from Georgia to Louisiana. They further show that a boy is fifty times as likely to do scientific work as a girl. No negro in this country has hitherto accomplished scientific work of consequence. A boy from the professional classes in New England has a million chances to become a scientific leader as compared with one chance for a negro girl from the cotton-fields.
These great differences may properly be attributed in part to natural capacity and in part to opportunity. When it is asked how far the result is due to each of these factors, the question is in a sense ambiguous. It is like asking whether the extension of a spiral spring is due to the spring or to the force applied. Some springs can not be extended, a foot by any force; no spring can be extended without force. The result depends on the relation between the constitution of the spring and the force applied. If the 174 babies born in Massachusetts and Connecticut who became leading scientific men had been exchanged with babies born in the south, it seems probable that few or none of them would have become scientific men. It may also be the case that few or none of the babies from the south transplanted to New England would have become scientific men, but it is probably true that a nearly equal number of scientific men would have been reared in New England. It is certain that there would not have been 174 leading scientific men from the extreme southern states and practically none from Massachusetts and Connecticut. If the stock of the southern states remains undiluted, it may, as social conditions change, produce even
