[72] Beeton, Miss M., Yule, G.U., and Pearson, Karl, _On the Correlation between Duration of Life and the Number of Offspring_, Proc. R. S. London, 67 (1900), pp. 159-171. The material consisted of English and American Quaker families. Dr. Bell's work is based on old American families, and has not yet been published. [73] The entire field of race betterment and social improvement is divided between _eugenics_, which considers only germinal or heritable changes in the race; and _euthenics_, which deals with improvement in the individual, and in his environment. Of course, no sharp line can be drawn between the two spheres, each one having many indirect effects on the other. It is important to note, however, that any change in the individual during his prenatal life is euthenic, not eugenic. Therefore, contrary to the popular idea of the case, the "Better Babies" movement, the agitation for proper care of expectant mothers, and the like, are not _directly_ a part of eugenics. The moment of conception is the point at which eugenics gives place to euthenics. Eugenics is therefore the _fundamental_ method of human progress, euthenics the _secondary_ one; their relations will be further considered in the last chapter of this book. [74] The clan has now reached its ninth generation and its present status has been exhaustively studied by A. H. Estabrook (_The Jukes in 1915_: Carnegie Institution of Washington, 1916). He enumerates 2,820 individuals, of whom half are still living. In the early 80's they left their original home and are now scattered all over the country. The change in environment has enabled some of them to rise to a higher level, but on the whole, says C. B. Davenport in a preface to Estabrook's book, they "still show the same feeble-mindedness, indolence, licentiousness and dishonesty, even when not handicapped by the associations of their bad family name and despite the fact of being surrounded by better social conditions." Estabrook says the clan might have been exterminated by preventing the reproduction of its members, and that the nation would thereby have saved about $2,500,000. It is interesting to note that "out of approximately 600 living feeble-minded and epileptic Jukes, there are only three now in custodial care." [75] Key, Dr. Wilhelmina E., _Feeble-minded Citizens in Pennsylvania_, pp. 11, 12, Philadelphia, Public Charities Assn., 1915.