152 PRINCIPLES OF FARM PRACTICE 



zation, and after it occurs the seed-producing body may 

 develop into a seed. 



The signihcance of fertilization lies in the fact that each 

 of the two bodies which unite in this process carries with it 

 characters of the parent producing it. If the fertilizing 

 bodies are from the same plant, the seed which is formed by 

 the union will produce a plant like the parent plant. But 

 if these bodies come from different plants, such as different 

 varieties of cowpeas, the seed formed from this union will 

 produce a plant in some respects unlike either parent, but 

 having some characters of each. In such instances the new 

 plant will combine the characters of both parents, although 

 some of the characters of each will dominate, or make ob- 

 scure similar characters of the other. 



By observing the principles of heredity, plant breeders are 

 able to combine the desirable characters of different parents. 

 Such a procedure is known as crossing or hybridizing. For 

 example, a smooth, bearded variety of wheat may be crossed 

 with a rough, beardless variety so as to produce a smooth, 

 beardless variety. This will be a combination of characters 

 that did not exist before, and in this case, probably a more 

 desirable combination than that possessed by either of the 

 parents. An almost endless variety of useful plants has 

 been developed in this way. ' 



Some of the results of crossing are so wonderful as to 

 attract wide attention. Perhaps the best known plant 

 breeder who made use of this method is Luther Burbank. 

 Among the plants that he has been able to develop are va- 

 rieties of plums, prunes, potatoes, chestnuts, walnuts, and 

 many flowers, such as the Shasta daisy. 



Scarcely less wonderful is the work of Professor N. E. 

 Hansen of the South Dakota Agricultural College. He has 



