1 90 Proceedings 



International. — Australian Association for the Advancement of Science: 

 Report, Vols, iii, iv, v. 



The Secretary was directed to cast the ballot of the 

 Academy for the following officers : 



President, ------- H. L. Osborn. 



Vice President, ----- W. X. Stidduth. 



Recording Secretary, - - - C. W. Hall. 

 Treasurer, ------ E. C. Gale. 



Corresponding Secretary, - - C. P. Berkey. 



Trustees for three years, - , l^- V- Winchell. 



IVerdine Trusdell. 



A paper on The Classification of the Sexual Affinities of 



Prtmus americana, by C. W. H. Heideman of New Ulm, was 



presented. 



[abstract] 



The uncertainty of regular annual fruiting of plums in the North- 

 west, where only the native Prunus americana in its many varieties 

 has been found sufficiently hardy to endure the climatic conditions, has 

 long been a difficult problem in Horticulture. The author undertook 

 to determine the causes underlying this recurring non-productiveness 

 in certain trees. 



An examination of plum flowers showed that the following types 

 occurred : 



Hermaphrodite — Stamens and pistil present and maturing at same 

 time. 



Proterogynous — Receptive period of stigma expiring before pollen 

 matures. 



Proterandrous — Pollen discharged before stigma becomes receptive. 



Long-styled — Style nearly twice as long as stamens. 



Short-styled — Stamens nearly twice as long as styles. 



Gyndoioecious — Anthers aborted. 



Andromonoecious — Pistils aborted. 



Hermaphrodite flowers are the only ones capable of self pollina- 

 tion, all the other types requiring cross-pollination. Trees with her- 

 maphrodite flowers are now rarely found in the wild state. 



By his experiments the author found that certain crosses produced 

 large, fine fruit while other crosses resulted in the production of in- 

 ferior fruit, or even no fruit at all. Of all the crosses possible between 

 plants bearing these different types of flowers he found that only the 

 eight following combinations would yield a desirable fruit: 



Hermaphrodite X Hermaphrodite. 

 Hermaphrodite X Proterandrous. 

 Hermaphrodite X Proterogynous. 



