Bisexual Crosses 285 



this species and its white variety has a blue 

 corolla. But occasionally it produces some 

 purely white flowers, showing parental heri- 

 tages, combined in its internal structures. Such 

 reversions are far from being common, but in 

 lots with thousands of flowering spikes one may 

 expect to find at least one of them. Sometimes 

 it is a whole stem springing from the under- 

 ground system and bearing only white flowers 

 on all its spikes. In other instances it is only a 

 side branch, which reverts and forms white 

 flowers on a stem, the other spikes of which re- 

 main bluish. Sometimes a spike even differen- 

 tiates longitudinally, bearing on one side blue 

 and on the other white corollas, and the white 

 stripe running over the spike may be seen to be 

 long and large, or narrow and short in various 

 degrees. In such cases it is evident that the 

 heritage of the parents remain uninfluenced by 

 each other during the whole life of the hybrid, 

 working side by side, but the active element al- 

 ways prevails over its latent opponent, and is 

 ready to break free whenever an opportunity is 

 offered. 



It is now generally assumed that this incom- 

 plete mixture of the parental qualities in a hy- 

 brid, this uncertain and limited combination is 

 the true cause of the many deviations, exhibited 

 by varietal hybrids when compared with their 



