286 Retrograde Varieties 



parents. Partial departures are rare in the 

 iiybrids themselves, but in their offspring the 

 divergence becomes the rule. 



Segregation seems to be a very difficult pro- 

 cess 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. 



Leaving this first generation, the original 

 hybrids, we now come to a discussion of their 

 offspring. Hybrids should be fertilized either 

 by their own pollen, or by that of other individ- 

 uals born from the same cross. Only in this 

 case can the offspring be considered as a means 

 of arriving at a decision as to the internal na- 

 ture of the hybrids themselves. Breeders gen- 

 erally prefer to fertilize hybrids with the pollen 

 of their parents. But this operation is to be 

 considered as a new cross, and consequently is 

 wholly excluded from our present discussion. 

 Hence it follows that a clear insight into the 

 heredity of hybrids may be expected only from 

 scientific experiments. Furthermore some of 

 the diversity observed as a result of ordinary 

 crosses, may be due to the instability of the par- 

 ents themselves or at least of one of them, since 

 breeders ordinarily choose for their crosses 

 some already very variable strain. Combining 

 such a strain with the desirable qualities of 

 some newly imported species, a new strain may 



