504 PLANT BREEDING 



483. Selection among beans. The common bean (Phaseolus 

 vulgaris) is of uncertain origin, but there is a good deal of evi- 

 dence to show that it came from western South America. Its 

 cultivation in Europe appears to have begun soon after the dis- 

 covery of America. As is well known, the number of varieties 

 in cultivation is very large, and in few plants is it easier than in 

 beans to produce new varieties by selection. 



Bean breeding for the large seedsmen is a skilled industry. 

 It is said that a seedsman may even advertise a new kind of 

 bean under an attractive name before the variety has been pro- 

 duced, then order it of his bean grower, and in the course of 

 two or three years have seed ready for his customers. On the 

 farm of one large bean grower nearly 70 standard varieties are 

 raised for seed on a large scale, and some 200 sorts are being 

 tested to establish their value or to produce new kinds. All pos- 

 sible pains are taken by means of high cultivation to increase the 

 bearing qualities of the plants and also to encourage variation. 

 Every variety, whether a standard one or a novelty, is kept to 

 the desired type by the careful inspection of every plant, those 

 which fall short in any respect being carefully destroyed. 



While new kinds are nowadays generally secured by scien- 

 tific plant breeding, sometimes valuable sorts are obtained from 

 chance seedlings, as in the case of a well-known dwarf Lima 

 bean which sprang from seeds gathered on a Virginia roadside 

 some time before 1885. 



484. Selection among corn. Indian corn was cultivated by 

 the ancient Peruvians and the Mexicans. Its original home as 

 a wild plant was probably on or near the west coast of South 

 or Central America. Numerous rather permanent kinds which 

 " come true from the seed " (races), such as field corn, sweet 

 corn, and pop corn, have long been known, and some of these 

 races present many varieties. 



Scientific corn breeding has been practiced for much less than 

 a generation, but the results already attained are of great 

 practical importance. 



