IMPROVEMENT OF PLANTS 49 



to distinguish between temporary improvement, and that 

 which will be permanent through later generations. 

 Usually an increase in the size of a plant due simply to 

 one year of special fertilizing, watering, or extra space is* 

 temporary. The large size, it seems, is not inherited by 

 the offspring. Improvement due to years of selection is, 

 however, inherited (Fig. 39). The most valuable plant for 

 seed purposes is not always the plant that happens to be 

 the largest, but rather the one that will produce productive 

 offspring of good quality. This is the reason why in a 

 seed-patch it is better to plant all the descendants of one 

 parent plant together in one row, so that the farmer may 

 judge the parent by the average character of the off- 

 spring. 



The farmer who would improve or " breed up " his corn, 

 cotton, wheat, oats, or other crop, should have a special 

 breeding plot or seed-patch and should carefully observe 

 each plant grown there. Sometimes it happens that there 

 is a single plant that is decidedly superior to all the others, 

 and seed of this " sport," or very unusual plant, may start 

 a new and more valuable variety. 



Home-grown seed often the best. If seed of corn grown 

 for many years in a colder country is brought to the 

 Southern states and seed from this variety planted for 

 several years in the South, each year the variety gets 

 later and later and the stalks larger and larger. 



If early vegetables are desired, make them earlier by 

 getting seed grown far North where the plant has learned 

 to be in a hurry to get ripe in a short season. Field corn 

 from north of the Ohio River is earlier and smaller, and in 



