134 Bulletin 251. 



greater milk production, improved beef quality, increased fecundity, 01 

 some such quality not changing the characters of the breed as a whole. 



The plant-breeder ordinarily strives to produce new races or breeds, 

 differing from the known sorts in some important characters by which the 

 variety or race may be recognized. The new varieties or races of the 

 plant-breeder would correspond to the different breeds of animals. 



The striving after markedly new varieties has led the plant-breeder 

 to largely overlook the advancement that may be wrought within the 

 variety by pedigree-breeding. 



The plant-breeder can handle tlwusands where the animal-breeder 

 handles tens. 



In careful pedigree-breeding, the animal-breeder follows both male 

 and female parents carefully selecting both. In the ordinary pedigree- 

 breeding in plants only the female parent is known and recorded, 

 although through planting the breeding stock in isolated fields, the male is 

 known to have come from a good mother parent. In some special cases 

 male and female are both followed in plants by practicing hand-pollina- 

 tion. 



In general, therefore, in plants the female is most generally followed, 

 while in animals the male is, if anything, considered most important. 

 In animals many herds are greatly improved by simply introducing a 

 good male ; in plants many crops are greatly improved by simply select- 

 ing good females as seed producers. 



What arc variationsf 



The fact that we are able to improve plants by selection depends upon 

 the occurrence of variations. We are accustomed to think of plants as a 

 whole as very stable and uniform. As we casually look over a field of 

 Ox-eye daisies and admire their beauty, we distinguish no apparent 

 variability ; all seem to be alike. Nevertheless, if we examine the plants 

 carefully and study the different individuals we find that each one 

 possesses certain peculiarities. Some have large flower heads, others 

 small flower heads ; some have very many rays or petals, others compara- 

 tively few ; some have broad rays, others narrow rays. Some plants are 

 tall, others short. Some plants are many flowered, others few flowered, 

 and the like. No two plants can be found which do not differ from each 

 other in some noticeable character. They present dift'erent facial ex- 

 pressions, the same as do people or cattle, so that we may recognize 

 different individuals apart after we have studied them and made their 

 acquaintance. We are not accustomed to being introduced to Sam 

 Ox-eye, Jim Ox-eye and John Ox-eye and attempting to recognize their 

 characteristics so we will know them when next they call. This, how- 

 ever, is one of the interesting studies which the breeder pursues. Care- 



