ON THE ROSE 



there were at least three or four others that are 

 similarly to be credited, although the exact pedi- 

 grees of all of them are not matter of record. 



Still the initial impulse to variation which sup- 

 plied the material for the new hybridizings, and 

 was thus primarily responsible for the outcome, 

 was given by the seeds gathered from the Her- 

 mosa. The same tendency to increased vigor and 

 productivity and variation that we saw manifested 

 in the case of the potato, and to which reference 

 has been made also in the case of the sugar-cane, 

 and of other plants that are usually propagated by 

 division rather than by cross-fertilization, was 

 doubtless given the seeds of the rose by a chance 

 mingling of just the right kind of pollen brought 

 by some vagrant bee with its usually unreceptive 

 ovules. 



The lesson that cross-fertilization gives vigor, 

 and provides the materials for variation, which we 

 have seen emphasized so many times, is here 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 devel- 

 opment in a given direction say as to its odor, or 



[47] 



