522 



VARIATIONS 



Also a number of our choice varieties of Wheat started from one 

 or a few plants which suddenly appeared differing in characters 

 from the other plants in the field. 



Although mutations are commonly described as wide depar- 

 tures in characters that appear suddenly and breed true there- 

 after, there are some exceptions. Sometimes mutations are 

 only small deviations from the normal type, and there are some 

 mutations that do not breed true but breed much like hybrids, 

 thus giving rise to offspring various in type. Professor Babcock 

 of the University of California gives an account of a new form of 

 Walnut differing in character of leaves, fruit, and in other ways 

 from the California Black Walnut from which this new form 

 apparently arose through a mutation. Some of the offspring of 

 this new form are true to the new type while others are like the 

 California Black Walnut. Other instances of mutations that do 

 not breed true have been noted. 



FIG. 470. The Wild Cabbage and some of the forms that are supposed to 

 be mutants of the Wild Cabbage. A, Wild Cabbage; B, Kohlrabi; C, Cauli- 

 flower; D, Cabbage; E, Welsh or Savoy Cabbage; F, Brussels Sprouts. 

 After Smalian. 



