HEREDITY AND VARIATION 265 



are " at once symptom, effect, and cause of evil." A city which 

 allows foul tenements, narrow streets, and crowded slums to exist 

 will spend too much for police protection, for charity, and for 

 hospitals. 



Every improvement in surroundings means improvement of the 

 chances of survival of the race. In the spring of 1913 the health 

 department and street-cleaning department of the city of New 

 York cooperated to bring about a " clean up " of all filth, dirt, and 

 rubbish from the houses, streets, and vacant lots in that city. Dur- 

 ing the summer of 1913 the health department reported a smaller 

 percentage of deaths of babies than ever before. We must draw 

 our own conclusions. Clean streets and houses, clean milk and 

 pure water, sanitary housing, and careful medical inspection all 

 do their part in maintaining a low rate of illness and death, thus 

 reacting upon the health of the citizens of the future. It will be 

 the purpose of the following pages to show how we may best care 

 for our own bodies and how we may better the environment in 

 which we are placed. 



REFERENCE BOOKS 



ELEMENTARY 



Hunter, Laboratory Problems in Civic Biology. American Book Company. 

 Bailey, Plant Breeding. Macmillan and Company. 

 Harwood, New Creations in Plant Life. The Macmillan Company. 

 Jordan, The Heredity of Richard Roe. American Unitarian Association. 

 Sharpe, Laboratory Manual, pp. 64-72, 345-347. American Book Company. 



ADVANCED 



Allen, Civics and Health. Ginn and Company. 



Coulter, Castle, East, Tower, and Davenport, Heredity and Eugenics. University of 



Chicago Press. 



Davenport, Heredity in Relation to Eugenics. Henry Holt and Company. 

 De Vries, Plant Breeding. Open Court Publishing Company. 

 Goddard, The Kallikak Family. The Macmillan Company. 

 Kellicott, The Social Direction of Human Evolution. Appleton Company. 

 Punnet, Mendelism. The Macmillan Company. 



Richards, Helen M. Euthenics, the Science of Controllable Environment. 

 Walter, Genetics. The Macmillan Company. 



