THE PLUM IN KANSAS, 



37 



cent, defective pistils. Obviously no crop can be expected from trees 

 which these samples fairly represent. Cases in which trees fail to set 

 fruit after being loaded with blossoms will be remembered by every 

 horticulturist. Doubtless many such instances of sterility occur 

 through lack of jjistils. The Marianna is notably a shy bearer. Its 

 record, as shown in table 1, seems to show a reason. Its evident sex- 

 ual weakness may also be some confirmation of its hybrid origin. 



The differences in the average percentages of defective pistils in 

 the several groups cannot be regarded as purely accidental. The 

 comparison may best be seen in table 1. 



From this it appears that about one-half of the pistils of the Mari- 

 anna were defective, over one-fourth in P. americana (the common 

 wild plum), only a little less in P. hortulana (the Wild Goose group), 

 about one-sixth in the Chickasaws and Japanese plums, and only one- 

 twentieth in the European varieties {^P. domestica). The great dis- 

 crepancy between the wild forms of the typical P. americana (mostly 

 Western) and the variety nUjra (mostly Eastern) is a point of con- 

 siderable interest. Besides furnishing another character in justifica- 

 cation of a division between the two forms, it gives a valuable hint to 

 those who are looking for new garden varieties. It is worth remark- 

 ing, however, in this connection that the variety nigra does not bear 

 so much pollen as the type forms. 



Some of the individual records in the laboratory examinations 

 are open to more or less explanation. For example, Mr. Munson 

 writes concerning a Wild Goose seedling (P, hortulana) which 

 showed 87.5 per cent, defective pistils : "It is only two years old from 

 seed, and is flowering for the first time. It is my experience that 

 almost invariably varieties, when they begin to bloom, set little or no 

 fruit. As they get age, some become very fruitful, while others always 

 fruit scatteringly. The youth of this tree, I think, fully accounts for 

 the defectiveness of the female parts."' It seems impossible, however, 

 with present data, to find any constant connection between defective- 



