AN INTRODUCTORY ORIENTATION 9 
race would avoid the danger of deterioration and realize the best 
of its hereditary possibilities we should know first of all what is 
the present trend of our development and what are some of the 
more important forces by which our development is guided. 
It is to a consideration of the forces which are modifying the 
inherited qualities of modern civilized peoples that the present 
book is devoted. The undertaking naturally leads us to discuss 
the inheritance of those human traits which are of especial signifi- 
cance in relation to the progressive or retrogressive development 
of mankind. After the first few chapters on this general topic the 
rest of the book is mainly concerned with a treatment of the 
selective agencies that determine what types of human inheri- 
tance tend to prevail over others, and the relation of these selec- 
tive agencies to various factors in our social environment. 
REFERENCES 
The following works of a more or less general character treat of a number of the 
topics discussed in the present volume: 
Ammon, O. Die Gesellschaftsordnung und ihre natiirlichen Grundlagen. Jena, 
1895. 
Ellis, H. H. The Task of Social Hygiene. Constable and Co., London, 1912, 
Houghton, Mifflin Co., Boston. 
Galton, F. Essays in Eugenics. Eugenics Education Soc., London, 1909. 
Grant, M. The Passing of the Great Race. Scribner’s, N. Y., 1916. 
Guyer, M. Being Well Born. Bobbs-Merrill Co., Indianapolis, 1916. 
Headley, F. W. Problems of Evolution. Crowell and Co., N. Y., rgor. 
Hill, G. Chatterton. Heredity and Selection in Sociology. A. and C. Black, Lon- 
don, 1907. 
Humphrey, S. Mankind. Scribner’s, N. Y., 1917. 
Kellicott, W. E. The Social Direction of Human Evolution. Appleton Co., N. Y., 
and London, 1915. 
Kelsey, C. The Physical Basis of Society. Appleton Co., N. Y., and London, 1916. 
McKim, W. D. Heredity and Human Progress. Putnam’s Sons, N. Y., and Lon- 
don, 1900. 
Pearson, K. The Grammar of Science, 2d ed. A. and C. Black, London, 1900. 
Popenoe, P., and Johnson, R.H. Applied Eugenics. Macmillan Co., N. Y., 1918. 
Reid, G. A. The Present Evolution of Man. Chapman and Hall, London, 1896. 
Rentoul, R. R. Race Culture or Race Suicide? W. Scott, London, 1906. 
Saleeby, C. W. Parenthood and Race Culture. Moffat Yard and Co., London and 
N. Y., 1911. 
Saleeby, C. W. The Progress of Eugenics. Funk and Wagnalls Co., N. Y. and 
London, 1914. 
