THE 



AMERICAN NATURALIST 



Vol. XLIII July, 1009 No. 511 



SELECTION IXDKX NTMIiERX AXI) TIIKIli I'SK 

 IX BREEDING 1 



tance of different theories as to the method of inheritance 

 for practical breeding, it must be recognized that the 

 vast majority of all the actual breeding operations which 

 are being carried on by plant and animal breeders at the 

 present time are conducted by some method of selection. 

 The belief is firmly held by most practical breeders that 

 the bulk of the improvement which has been made in 

 domestic plants and animals has been as the result of 

 selection. While it is also coming to be recognized that 

 hybridization may play an extremely important part in 

 breeding operations either by cau>in<r increased variation 

 or by bringing about a recombination of characters, ac- 

 cording to Mendelian principles, yet selection must always 

 be used as a supplement to hybridizing in practical breed- 

 ing. The higher degrees of perfection demanded in judg- 

 ing ring and show room are only attained by the most 

 careful and close selection. The manner in which sue- 



