2IO PLANT-BREEDING 



extremely rich in garden varieties and thus affords excellent 

 material for hybridizations. The affinity between the two 

 species is very small and the crosses have only succeeded in 

 one direction. The oriental species does not accept the 

 pollen of the somniferum even if it is placed upon its stigma, 

 but remains wholly sterile under its influence. The recipro- 

 cal cross in which the oriental is the pollen parent, produces 

 some few seeds, but from these hybrids arise with a remark- 

 able degree of variabihty in their fohagc and flowers. The 

 hybrids themselves arc also almost sterile, some producing 

 no flowers at ah; others only small ovaries or miscarried 

 ones reduced to a sharp point on the top of the flower stalk. 

 They can, however, be fertilized with the pollen of the opium 

 poppy, and by doing so a second generation of hybrids has 

 been produced. This generation grew by the side of the 

 first one on a bed of Burbank's home farm, when I visited 

 him, and was seen to be extremely variable in its fohage 

 and in its manner of growth, whether annual or perennial. 

 Each individual was typical, having all of its leaves of the 

 same shape, color, and hairiness, but among them hardly 

 any two were aHkc. Selection must still be made, and the 

 selected individuals must be crossed again in order to secure 

 still more beautiful garden flowers. 



I am now coming to the description of the most celebrated 

 of all Burbank's crossings, those of the plums. In a large 

 portion of the southern states, where the European varieties 

 of plums had yielded only failures, notwithstanding long and 

 careful attempts, the new hybrids are claimed to make plum- 

 growing possible. In many parts of CaHfornia plum culture 

 is said to become more profitable by the introduction of some 

 of Burbank's hybrids, and a new epoch of fruit-tree growing 

 has thereby been opened. Hardiness and productiveness 

 are the main features by which these results have been 

 secured, and they themselves were obtained by the combina- 



