ice) DOMESTICATED ANIMALS AND PLANTS 
plant production tends strongly to the deterioration of the soil. 
Besides this, both animals and plants must be brought and kept 
up to the highest standard of efficiency, and it is the purpose 
of this book to discuss some of the principles involved in secur- 
ing and maintaining the highest attainable service on the part 
of both animals and plants; in other words, their systematic 
improvement from the standpoint of usefulness to man. 
This being true, we cannot know too much about them, — 
their nature, their history, and the significant details of their re- 
production and development. Accordingly, first of all, attention 
is invited to the source from which they have come down to us. 
Summary. We are absolutely dependent upon plant and animal life for 
food, clothing, and heat, and very largely so for light, shelter, labor, recrea- 
tion, medicinal compounds, and the raw material for manufacture. In a very 
large sense man has drafted into his service all other living things which 
seem capable of ministering to his prosperity; thus, if in no other way, 
proving his superiority over all other created beings. 
Exercises. 1. Write essays showing what the horse has done and is 
doing for man. 
2. Write essays showing how we would be affected, and how we would 
get on if we should suddenly be deprived of the cow. 
3. What is the most useful domestic animal in your neighborhood, 
and why? 
4. What is the most important crop of the locality, and why? 
5. Calculate the value of all the animals of the United States and of your 
own state, and express it not only in totals but on the per capita basis. 
6. In the same way estimate the annual output of crops, and compare 
with this the value of our exports. 
7. Do the same for the animal products, meat, milk, and wool. 
8. Calculate the amount and value of the grain and hay consumed 
annually by our domestic animals, and compare it to the cost of feeding our 
human population. 
Reference. Year-Book, United States Department of Agriculture. 
