many trees of the clonal variety that may be propagated from 

 branches are fruitless unless there is compatible cross-pollination 

 from trees of another clonal variety. This is the reason for in- 

 teiplanting those clonal varieties of apples that are fully or de- 

 cidedly self-fruitless. 



One can scarcely expect the seed of an apple tree to breed 

 true even though the tree may be a member of a pure species. 

 In private plantings, in botanical gardens, in arboretums, and in 

 collections of species and varieties of the apple such as the one 

 at the State Experiment Station, there is abundant opportunity 

 for cross-pollination between species. But when in addition a 

 lone representation of a species in such a collection is fully self- 

 incompatible all its seed must necessarily be of hybrid origin. 

 Seed collections from such sources can not be relied upon to 

 come true to the seed parent. 



It is not surprising that this type of self-sterility should exist 

 among the individuals of various species of wild apples. They 

 have evidently transmitted this characteristic to the varieties now 

 in cultivation. It is, however, favorable to the interests of hor- 

 ticulture that some individuals, of certain species at least, and 

 some of the clonal varieties now grown in orchard culture are 

 self-fruitful. The}^ do not need cross-pollination and if highly 

 self-fruitful may be grown in solid blocks without a necessary 

 decrease in yield because of incompatible pollination. 



Those who are breeding apples to secure new and better sorts 

 for culture will without doubt in the future give special atten- 

 tion to the obtaining of individual seedlings that are highly self- 

 fruitful. 



A. B. Stout. 



