A VISIT TO LUTHER BURBANK. 347 



and the Siberian raspberry. Both have small and insignificant fruits, 

 while the hybrid on this point greatly surpasses either parent. In 

 Europe we have long known similar instances through the studies of 

 wild hybrids by Kerner, and by Wichura, Janzewsky and many other 

 writers regarding cultivated bastards. 



If the relationship between species is not close enough, all attempts 

 to hybridize are frustrated. Either the crossing is a failure, and no 

 seeds are produced, or hybrids are obtained which are infertile. In the 

 case of flowers this is not of so much importance, but in regard to fruit 

 trees such a result is a complete failure. It is evident that nature has 

 here drawn a limit which man can not cross. This boundary line is, 

 however, not marked, and consequently once in a while surprising re- 

 sults are obtained. Hybrids which are infertile in thousands of cases 

 may for once prove a success among hundreds of thousands. Burbank 

 has an example of this in his crossing of Petunia with tobacco. From 

 numberless hybrids he got one germinating from seed. He named this 

 curiosity Nicotunia (from Nicotiana and Petunia). It was not very 

 attractive and succumbed after one year, having flowered profusely, 

 but failed to produce any seed. 



It is unfortunate that we can not see this limit of nature in advance, 

 but have to learn it by experience. And this experience includes an 

 almost incomprehensible amount of labor of which no one hears any- 

 thing. 



