QUESTIONS 31 



able to grow the best tubers. The statement is often made 

 that potatoes must be renewed from the seed-ball fre- 

 quently, in order to keep up their yield. If carefully 

 selected and well grown, the present varieties would doubt- 

 less maintain their yield indefinitely. When poor potatoes 

 are planted and poorly cared for, they will surely deteri- 

 orate. It is probable that new varieties will continue to 

 be formed from the seed that are better than any of the 

 present varieties, so that even if present varieties are im- 

 proved they are certain to be displaced eventually. Old 

 varieties cannot be renewed from the seed because pota- 

 toes do not come true from seed. 



33. Plant-breeding Farms. Farms whose business is 

 the production of improved varieties of plants are now 

 beginning to develop in different parts of this country. 

 Several such establishments have been in operation for 

 a number of years in Europe. In time, farmers will likely 

 come to look to these farms for seed, as they now go to 

 stock-farms for pure-bred stock. If improved seeds are 

 really produced, they must be sold for an increased price. 

 Improvement, such as can be practiced on any farm, 

 as described in the preceding paragraphs, is not very ex- 

 pensive. But to produce new types of plants that are 

 better than anything else that now exists is expensive. 

 When once produced, they are too valuable to be grown 

 by one man only. 



QUESTIONS 



1. What is protoplasm? 



2. What are the worst ten weeds of the neighborhood? Look them 

 up in the botany manual and see which were introduced from Europe. 

 What are the characters of each that make it able to persist? 



