Balanced Crosses 285 



this species and its white variety has a blue 

 corolla. But occasionally it produces some 

 purely white flowers, showing its power of sep- 

 arating tlie parental heritages, combined in its 

 internal structures. This reversion is not com- 

 mon, but in thousands of flowering spikes one 

 may expect to find at least one of them. Some- 

 times it is a whole stem springing from the 

 underground 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 remain bluish. Sometimes a spike even 

 differentiates 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 heritages of the parents remain un- 

 influenced by each other during the whole life of 

 the hybrid, working side by side, but the active 

 element always prevails over its latent opponent 

 which is ready to break free whenever an oppor- 

 tunity 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 



