EXPERIMENT STATIONS. 189 



with pollen of Early Red (Russian) set no fruits. Ten blossoms 

 pollinated with pollen of Caroline, one of my seedling's, developed 

 fruits inferior to those of the self-fertilized Wolf. As a check on fer- 

 tilization, ten blossoms were self-pollinated, and they developed fair 

 fruits but inferior to those fertilized by Hiawatha and Hammer, 

 thoug-h superior to the other crosses. These crosses were all made 

 on one tree, on different daj^s. The blossoms operated on were all at 

 about the same stage of maturity and were carefully protected until 

 the fruits set. The individual differences within the same group 

 were scarcelj^ noticeable, but were quite marked when the different 

 groups were compared. Other crosses were made which as clearly 

 showed the adaptiveness of the pollen of certain varieties over other 

 varieties. 



The idea of mixed and close planting of varieties may be carried 

 too far and in the wrong direction, unless a study is made of the 

 secondary effects. My attention was first attracted to the possi- 

 bility of inflvxeucing the size and qualitj^ of plums by the use of the 

 right pollen bj' the following fact, which alone is accountable for in 

 no other way' than except by the direct influence of foreign pollen: 

 A chance seedling was planted on ray grounds almost vmder the lean- 

 ing- top of a tall Weaver plum tree ; for several years the fruit was 

 a large, flatfish, oblong freestone of good quality and very product- 

 ive. The plum being so much better in quality than the Weaver, 

 the Weaver tree w^as cut down the next season and ever since the 

 fruit has been smaller, nearly round and a perfect clingstone. J^ast 

 spring, I applied pollen from the Weaver to a few blossoms, and the 

 fruits clearl)^ showed the effect of the Weaver pollen. 



The effect may sometimes be observed only in the seeds. Last 

 year, while opening some heps of the native wild rose (rosa Virgin- 

 iana), which had been hybridized with various hybrid remontant 

 roses, I noticed several seeds which were larger than, and different in 

 color and shape from, the rest of the seeds in the saine hep. The)^ were 

 so near like the pure seeds of remontant roses that I concluded the 

 seeds had got into the pan in which I was washing them by acci- 

 dent, and I threw them away. The very next hep that I opened 

 contained several seeds of the same character. These seeds were 

 planted separately and produced seedlings which can scarcely be 

 distinguished from remontants and show no hybrid character as 

 yet. The balance of the seeds produced seedlings like R. Virginiana, 

 and among them some which showed the hybrid characters. 



I am aware that scientific men at several experiment stations 

 have experimented in this direction and have come to the conclu- 

 sion "That as far as immediate secondar}- effect of pollen is con- 

 cerned upon rosaceous plants, which comprise our apples, plums 

 and cherries, there is a dispute, and that the weight of authority in- 

 dicates an absence of immediate effect." 



With due deference for the opinions of these gentlemen, can they 

 explain the above, or the case of the plum changing in size and 

 quality and from a clingstone to a freestone, by any other theory 

 than that betn^een slightly differentiated individuals of the same 

 species there is an immediate secondary effect of foreign pollen? 



