SOME INTERESTING FAILURES 



in size until it finally dropped from the bush in 

 the fall. 



The following season a few of the plants bore 

 one or two fruits having two or three drupelets 

 each, like mere fragments of a normal raspberry. 

 But not a seed was found. The plants were as 

 sterile as mules. So here the experiment ended, 

 and the hybrid strawberry-raspberries followed 

 the hybrid dewberries to the brush heap. 

 Why the Experiments Paused 



If now we consider the results of these various 

 experiments, it will be clear that they have certain 

 elements in common. In all cases the hybridizing 

 was effected between species that are botanically 

 related. Some of them (petunia and potato, dew- 

 berry and its mates, strawberry and raspberry) 

 belonged to different genera, however, and in no 

 case was the relationship between the mated 

 forms very close. And this fact is of course of 

 salient importance in enabling us to comprehend 

 the results. 



It is almost axiomatic to say that the hybrid- 

 izing of plants becomes increasingly difficult in 

 proportion as the attempt is made to cross more 

 and more distantly related species. Even within 

 the same genus it is very often impossible to 

 produce a hybrid that is not sterile. 



I might cite in further illustration of these 



[295] 



