6 REASONS FOR THE STUDY OF BIOLOGY 



and because it holds water in the earth. It keeps the water from 

 drying out of the soil quickly on hot days and from running off 

 quickly on rainy days. Thus a more even supply of water is given 

 to our rivers, and freshets are prevented. Regions that have 

 been deforested, such as parts of China, Italy, and France, are novv 

 subject to floods and are barren in many places. On the forests 

 depend our supply of timber, much of our water power, and the 

 commercial importance of navigable rivers. 



Biology in Relation to Society. — The study of biology also ought 

 to make us better men and women by teaching us that unselfish- 

 ness exists in the natural world as well as among the highest 

 members of society. Animals, lowly and complex, sacrifice their 

 comfort and their very lives for their young. In insect colonies 

 the welfare of the individual is given up for the best interests 

 of the community. The law of mutual give and take, of sacrifice 

 for the common good, is seen everywhere. This should teach us, 

 as we come to take our places in society, to be willing to give up 

 our individual pleasure or selfish gain for the good of the com- 

 munity in which we live. Thus the application of biological prin- 

 ciples will benefit society. 



Biology in Relation to Citizenship. — Finally, proper qualifica- 

 tions for citizenship are the biggest return we uisij expect from 

 our high school career. How can a man or woman become an 

 intelligent voter without at least some understanding of biology? 

 Think of the number of times the average voter is asked to ex- 

 ercise judgment on matters concerning the health and wealth of 

 the community. How can he do this without some knowledge of 

 the facts ? And how can he exercise judgment if he has no previous 

 training? Science, especially through experiments, helps us to 

 make intelligent judgments. Through the projects and experi- 

 ments you carry out, your ability to think straight as a citizen 

 will be aided. And when we realize that in the last half century 

 the application of biology to health has lengthened the average 

 span of life ten years ; when we see that applications of biology in 

 industry have made the life of the average workman far safer than 

 before, we understand the need of real knowledge of applied biol- 

 ogy. It is the purpose of this book to help the boys and girls of 

 to-day to become healthy, intelligent, thinking voters of to-morrow 



