ENVIRONMENT 
537 
biology. When the environment of man is critically studied, 
it is noted that it may have a large influence upon him. 
Even though he may have inherited a strong body and a 
tendency to thrift and industry, he may find himself in a 
social environment that is so strong that he has great diffi¬ 
culty in earning enough money to keep alive. When the 
full influence of environment was appreciated, men and 
women began to insist that better housing conditions and a 
certain amount of fresh air and light must be provided in 
order that those who lived in the tenements should find it 
easier to keep well and thus be able to work. Even though 
their environment be not of the best, it is possible for them 
to become superior to it. 
In the steady advance which human progress is making, 
the conditions under which men and women live and work 
are constantly growing better. As these conditions improve, 
there will naturally follow a larger opportunity for our in¬ 
heritance to have its full influence upon us. Two note¬ 
worthy movements are already having a marked influence 
in this direction; namely, the prevention of the spread of bio¬ 
logical diseases and the child welfare movement (see page 
513). As we gain a clearer conception of the importance 
to man of variation and heredity, other movements will be 
undertaken to place man in greater control of his environ¬ 
ment. 
The fact that biology stimulates us to think about all 
such problems is one of the main reasons for studying it. 
But with all this scientific information at our disposal, much 
remains for the individual to do. He must realize his 
obligations and opportunities in the age in which he lives. 
A mere passive existence has never accomplished anything 
worth while. The desire to serve our country and our fellow- 
man and a personal ambition must be added to our scientific 
information, if we would attain real success. 
