THE ROSE 231 



given a fresh illustration. It is a lesson that 

 the grower of roses and other long-cultivated 

 flowers may well bear in mind. 



When the resources of selection have been 

 practically exhausted, and a particular variety 

 of flower has reached a static period, in which it 

 seems to present no further opportunity for 

 development in a given direction say as to its 

 odor, or its color, or its size the plant experi- 

 menter should never forget that there still lies 

 open to him the possibility of introducing new 

 elements of variability, and new opportunities 

 for improvement, through hybridization. 



This, of course, assumes that the flower has 

 not been so specialized that all its stamens have 

 been transformed into petals, so that it becomes 

 absolutely sterile. Such a transformation has, 

 indeed, been effected with a good many of the 

 cultivated flowers, including some of the roses. 

 And the case of Hermosa, just cited, illustrates 

 the fact that some of our roses are practically 

 sterile. Indeed most of them are so. 



But then the flower that has ceased to have 

 productive stamens may sometimes still have a 

 receptive pistil, so that new blood may be intro- 

 duced from a species that retains normal virility 

 although in general, such flowers show small 

 capacity even for accepting the pollen. 



