546 GENERAL BIOLOGY — A REVIEW AND SUMMARY 
coming in contact with the great world of nature. So we 
find that as man is compelled to live in cities, where highly 
specialized conditions deprive him of the pleasures of the 
natural world, he is constantly adding to the parks and 
“ breathing places ” where he may go and “ commune ” 
with nature. 
Everywhere we see this tendency of man’s nature to get 
into contact with the real, natural world. House plants, 
birds in cages, bird-nesting boxes in the yard, trees by the 
roadside and flower gardens at the door — all these are re¬ 
sults of man’s efforts to commune with nature. 
Review the following : section 29; and figures 33, 37. 
416. Conservation. — As man has utilized some of the 
plants and animals for his advancement he has, in many 
cases, so wantonly handled them that there is danger of the 
supply being exhausted. In his haste for lumber to build 
houses and barns, he is selfishly cutting down trees in great 
quantity and leaving not sufficient to grow for the next 
generation. In his anxiety to get a big catch of fish, he has 
been catching so many as to leave none to lay the eggs for 
a new generation. Almost before we were aware of the dam¬ 
age that was being done, some animals and plants had been 
exterminated. 
Now we are looking ahead to see where the future lumber 
is going to grow; as a result we have forestry schools. Now 
we are thinking of the wild life that is growing less in num¬ 
bers and variety, and we are passing laws to protect it. Some 
one has said that we are merely guardians of the wild life, 
and that we must account for our stewardship to the gen¬ 
erations that come after. It would not do to pass on to 
future generations an earth depleted and robbed of wild 
life and made up of barren hills and rain-washed slopes. 
So we are interesting ourselves in this big question of con¬ 
servation, which is really acting as stewards of the earth 
for the benefit of the people who are to follow us. Every 
