BOTANY OF THE POTATO. 19 



of food in the cells of the seeds. Hence, it frequently 

 happens that early potatoes concentrate their energies so 

 fully in storing up food in the tubers that they fail to 

 produce flowers or perfect seeds. The main object of cul- 

 tivating the potato is to secure an abundance of large 

 tubers, and so we feed the plant liberally with that object 

 in view; in other words, we encourage it to devote all 

 its energies to tuber production. If we wanted a potato 

 plant to yield flowers and berries in preference to tubers, 

 we should attempt to discourage the formation of too 

 many tubers, arid so divert the manufactured food to the 

 formation of seeds, by growing the plant in a poorer soil. 



So far as the perpetuation of a potato is concerned, a 

 tuber is as good as a seed. The tuber, as previously ex- 

 plained, contains reserve food for supporting the young 

 growth till it can begin to put forth roots of its own, and 

 collect its own soil-food. Directly it is placed in the moist 

 earth, or if it is stored in a warm place, heat and moisture 

 penetrate the skin of the tuber, oxygen is absorbed, and 

 this, combining with the cell nutriments, chemically 

 changes the starch into sugar, and provides the special 

 form of food which the bud or eye requires to induce it to 

 begin to grow. Precisely the same thing occurs in the 

 case of a seed. When leaves are formed, as well as roots, 

 the former collect food from the air, called air-food, and 

 the latter food from the soil, called soil-food. 



The story of the office and development of a tuber or 

 seed has been told in as simple language as possible, in 

 order that the novice in botany and plant physiology may 

 understand the matter with ease. To the scientific reader, 

 the facts we have set forth are well known and under- 

 stood in a fuller degree than we have described. 



c 2 



