An instance is given by the long-leaved veronica (_Veronica longifolia_), which has bluish flowers in long spikes. The hybrid between [285] this species and its white variety has a blue corolla. But occasionally it produces some purely white flowers, showing its power of separating the parental heritages, combined in its internal structures. This reversion is not common, but in thousands of flowering spikes one may expect to find at least one of them. Sometimes 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 uninfluenced 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 opportunity is offered. It is now generally assumed that this incomplete mixture of the parental qualities in a hybrid, this uncertain and limited combination is the true cause of the many deviations, exhibited by varietal hybrids when compared with their [286] parents. Partial departures are rare in the hybrids themselves, but in their offspring the divergence becomes the rule. Segregation seems to be a very difficult process in the vegetative way, but it must be very easy in sexual reproduction, indeed so easy as to show itself in nearly every single instance.