90 Plant-Breeding 



What do new characters come from ? If mutations are 

 the result of the appearance of new characters or the loss 

 of old ones, where do these new characters come from 

 and what causes the loss of existing ones? The answer 

 to this question would give us the keynote to the whole 

 situation. If breeders possessed definite knowledge of 

 the cause of mutations, they would then have within 

 their control a kind of variation which could be made 

 of tremendous economic importance. The causes are 

 evidently from an internal origin. In all probability, 

 many so-called mutations are due to hybrid origin and 

 in the strictest sense are not mutations at all, even though 

 they may be bred true. Much experimental evidence 

 is necessary to determine with certainty their cause and 

 control. 



Can mutations be produced artificially ? Must breeders 

 passively wait for mutations to arise, or may they be 

 produced artificially? Many experiments are now being 

 conducted to test this. So far, experiments do not seem 

 to have led to any definite conclusion. 



Economic significance of mutations. Agricultural and 

 horticultural literature is full of accounts of the sudden 

 origin, or at least the sudden finding, of exceptionally good 

 plants which, when propagated, became the progenitors 

 of new and valued races. So great is their number that 

 not even an attempt to catalogue them can be made here. 



The pages of " Evolution of our Native Fruits" (Bailey) 

 are filled with examples of mutation. The experience of 

 plant-breeders and nurserymen show the origin of many 

 varieties in this way. 



Many observing growers of cereals and other plants 



