MAKING NEW KINDS OF PLANTS 421 



fan -like as in the Cockscomb, or when the edges of 

 the leaf unite and cause it to assume the form of a 

 pitcher, as happens not infrequently in various plants. 



Sudden variations may or may not come true to 

 seed. The greatest importance is attributed to them 

 by Professor de Vries, as will be seen later. 



Whoever wishes to improve plants must be on 

 the alert to seize upon variations, whether they be 

 of the ordinary fluctuating kind or sudden variations. 

 Ordinarily only favorable ones will be preserved, but 

 when these do not occur the plant -breeder may con- 

 tinue to propagate the most variable individuals, 

 hoping that in time favorable variations will occur. 



By varying the conditions of culture 1 and climate 

 (described in Chapter VIII), it is possible for the 

 breeder to produce variations in the desired direction, 

 or, as he says, "break the type." Some plants respond 

 very readily to that treatment: others do not. In 

 general, however, this is a tedious process and of 

 very small value as compared with crossing. 



By crossing, the breeder can create almost endless 

 variations and at the same time direct them in the 

 desired channels. Crossing means the fertilization of 

 a plant with pollen from a different variety or species. 

 The result of the cross is called a hybrid. 2 



1 See an article by Webber in the Year -Book of the United States 

 Department of Agriculture for 1896. 



2 See Bailey: "Plant Breeding." See footnote on page 420. Also an article 

 by Swingle and Webber in the Year -Book of the United States Department 

 of Agriculture for 1897. 



