CHAPTER II. 

 THE GROWTH OF A SEED. 



The prime object of the plant's existence is to prepare for the perpetuation 

 of its kind. In some plants, the whole force of its vitality is expended in 

 one season, in the production of a large crop of seed, in the growth of which 

 the plant is exhausted, and it perishes after the seeds are formed. Such 

 plants enduring but for a summer, we call annuals. 



There are others that spend the first year of their existence in the storing 

 up in roots a great accumulation of food, which they exhaust the next season 

 in the production of seed, and they, too, then perish. These are called 

 biennials, or two year plants. Others store up growth of larger dimensions, 

 year after year, and finally, when strong and well matured, give some of the 

 accumulated vitality to the production of fruit and seed, and continue to do 

 so for many years ; some for hundreds of years, having a rather indefinite term 

 of existence. These we call perennials, or plants living through a long series 

 of years. Still another class accumulate during years of growth, long or 

 short, a great store of food, and finally make the supreme effort of their lives 

 in the production of a vast growth of flowers and fruit, and then perish. To 

 this class belong the plants known as Century plants, the American Agaves 

 and others. 



The plants that farmers depend upon for crops are chiefly the annual and 

 biennial classes. 



THE FLOWER. 



The flower of a plant is considered by botanists to be really a collection 

 of leaves, changed in various ways to serve the purpose of reproduction. 

 Every complete flower has two protecting coats ; the outer one called the calyx 

 is commonly green, but is sometimes brightly colored. The inner circle of 

 transformed leaves is called the corolla, and its separate leaves are called 

 petals , while those of the calyx are called sepals. The inner circles of leaves 

 are still further transformed so as to make stamens and "pistils. On the sta- 



(24) 



