44 



AGKICULTURE 



life purpose of the plant. As soon as they mature, its work is 

 done. Its roots cease to take in food and water, its leaves cease 

 to manufacture starch and sugar, and the plant dies. 



Annuals. This is the life history of an an'nu al, such as our 

 agricultural cotton, which lives only one year and produces one 



crop of seed. 



Biennials. Some plants, 

 such as the turnip, do not 

 produce seed the first season. 

 They make a part of their 

 growth one summer, live 

 through the winter, blossom 

 and produce seeds, and die 

 the second year. These plants 

 are called bi gn'ni als. 



Perennials. There is a 

 third class of plants called 

 per Sn'ni als, which take still 

 longer to make their growth. 

 They live three or more years, 

 usually growing in the sum- 

 mer and resting in the winter. 



Perennials often bear many crops of seed; sometimes, as in the 

 case of the oak, they are slow of growth and live many years 

 before they begin seed bearing. 



It is an interesting fact that cotton is by nature a perennial. But 

 the plant that grows in our field is an annual. It has been made so 

 by the work of man. He has used conditions of soil and climate, cul- 

 ture, and fertilizers to shorten its period of growth, and thus change 

 it from a perennial to an annual. Later, we shall learn more of the 

 influence of man on the development of our agricultural plants. 



AN OPENED COTTON BOLL 



