ENVIRONMENT OF PLANTS AND ANIMALS 27 



to be placed close together, or piled on top of each other, as in the 

 modern apartment. Fields and trees, all outdoor life, has practi- 

 cally disappeared. Man has come to live in an artificial envi- 

 ronment. 



Care and Improvement of One's Environment. Man can 

 modify or change his surroundings by making this artificial en- 

 vironment favorable to live in. He may heat his dwellings in 

 winter and cool them in summer so as to maintain a moderate and 

 nearly constant temperature. He may see that his dwellings have 

 windows so as to let light and air pass in and out. He may have 

 light at night and shade by day from intense light. He may have 

 a system of pure water supply and may see that drains or sewers 

 carry away his wastes. He may see to it that people ill with 

 " catching " or infectious dis'eases are isolated or quarantined from 

 others. This care of the artificial environment is known as sanita- 

 tion, while the care of the individual for himself within the environ- 

 ment is known as hygiene. It will be the chief end of this book tc 

 show girls and boys how they may become good citizens through 

 the proper control of personal hygiene and sanitation. 



REFERENCE BOOKS 



ELEMENTARY . 



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

 Hough and Sedgwick, Elements of Hygiene and Sanitation. Ginn and Company. 

 Jordan and Kellogg, Animal Life. Appleton. 



Sharpe, A Laboratory Manual for the Solution of Problems in Biology, p. 95. Amer- 

 ican Book Company. 

 Tolman, Hygiene for the Worker. American Book Company. 



ADVANCED 



Allen, Civics and Health. Ginn and Company. 



