274 



General Botany 



now grown in orchards started in this way from perhaps a single 

 tree. 



The most valuable fiber plant known is a new variety of " long- 

 staple " upland cotton. It was produced by hybridizing or 

 breeding together two well-known varieties of Egyptian cotton. 

 Among the numerous varieties obtained from this cross was one 

 whose seeds were covered with hairs an inch to an inch and 

 a half in length. This variety has been propagated by the 

 United States Department of Agriculture and is now widely 

 grown. 



The Concord grape is now grown in most temperate regions 

 of the earth. It was produced by Ephraim Bull in New York 

 by crossing two wild species, and was one plant selected in 1853 

 from among 22,000 seedlings tested. 



Breeding for increased yield. The way in which the yield per 

 acre may be increased is strikingly illustrated by a tobacco dis- 

 covered and distributed by the Connecticut Experiment Station. 

 The usual varieties of tobacco develop about twenty leaves and 



Fig. 172. Fiber from new varieties of long-fibered cotton at the right, obtained by hybridiz- 

 ing and selecting progeny from the two forms producing the shorter fibers at the left. The 

 hybrid offspring excel both parents in the length of fiber produced. 



