CHAPTER XXXV 



PLANT 



AND ANIMAL 

 BREEDING 



Speed Horse. 



Dray Horse. 



What are some of the results of plant and animal breeding? What 

 are some of the methods used by plant and animal breeders to improve 

 the variety? 



Importance of plant and animal breeding. It is only a little 

 over one hundred years ago that the English clergyman, Malthus, 

 wrote his famous essay setting forth the principle that population 

 tends to increase much faster than the supply of food. He believed 

 that famines, wars, and plagues were useful, at least, in limiting 

 the population that otherwise would be doomed to slow starvation. 



What is the situation to-day ? Since the time of Malthus, the 

 population of Europe has nearly trebled, and in the United States 

 it has increased approximately ten times. Yet famines are no 

 longer experienced except in those countries with poor transporta- 

 tion facilities. The world as a whole has at no time been so well- 

 fed nor had so great a variety of foods. Malthus contributed a 

 fact of real value to mankind in calling attention to the rate of in- 

 crease of the population. Since that time, modern farm machinery, 

 good transportation, and knowledge of food preservation have all 

 aided an increasingly smaller proportion of the people of the world 

 to provide sufficient food from the farms for the needs of all. 



Another factor which has greatly increased the production of 

 food, and which is of particular interest to the biologist, is the 



343 



