IMPROVEMENT OF PLANTS. 



25? 



has made a growth (^( sever;;! inches, 

 place a rouiui, sirai^l.l r.tick in ihe pot 

 for its support, ami i)in(l it lo it with a 

 soft string, leaving al)out two inches of 

 the top of the plant free. When this free 

 portion has bent directly toward tlie 

 light, gradualh' turn the pot so that as 

 the tip again turns toward tiie light the 

 stem will at the same time make a par- 

 tial revolution around the support. 

 (Fig 82). 



Continue turning the pot in this 

 manner throughout the growth of the 

 plant. As the plant develops, it would 

 be well to give it more light, but this 

 should always be obtained from a 

 northern exposure. 



(^) \'ariation Induced by 

 Pruning (Fig. 83). — Not only is 

 the food-supply distributed to a 

 less number of branches, thereby 

 increasing the amount to each 

 branch, but the /or;;i of the en- 

 tire pla7it can be greatly inodijied 

 by pruning. 



Buds or branches may be ac- 

 cidentally destroyed or intention- 

 ally removed. As an example of 

 variation induced by accident 

 may be given the origination of the Burpee 

 Bush Lima bean. 



In 1883 " Mr. Palmer's entire ci'op of large 

 White Pole Limas was destroyed by cutworms." 



FIG. 82. — POTATO 

 PLANT. 



Voluble stem pro- 

 duced by Experi- 

 ment 2y. 



