SCIENTIFIC PROCEEDINGS. 



Abstracts of Communications. 

 Eighty-eighth meeting. 



College of Physicians and Surgeons, January 16, iqi8. 

 President Gies in the chair. 

 138 (1316) 



Experimental studies of self-incompatibilities in fertilization. 

 By A. B. Stout (by invitation). 

 [From the Botanical Gardens, Bronx Park, N. Y.] 



The phenomenon of self-incompatibility in the fertilization of 

 hermaphrodites is well illustrated by conditions existing in the 

 common chicory plant {Cichorium Intybus). The flowers are 

 perfect, they are anatomically all alike, the flowers are open only 

 for a short time so that pistils and stamens are ready for pollina- 

 tion at the same time, and the parts are decidedly adapted for 

 self-pollination, and yet when controlled self-pollinations are 

 made many plants, set no seed. Many cross-pollinations are 

 also incompatible, but both pollen and pistils will function in 

 certain crosses. The inability to set seed to self-pollination (or 

 cross-pollination as well) is here best described as due to some sort 

 of physiological incompatibility operating between sex organs 

 (including sex cells themselves) that are fully formed, anatomically 

 perfect, potentially functional and of simultaneous development. 



Studies in chicory have been pursued by the writer during the 

 past six years. Nearly 2,000 plants (all but the first crop were 

 pedigreed) have been studied and controlled pollinations made of 

 heads comprising a total of over 450,000 flowers. There is thus 

 available more data on self-compatibility for this plant than for 

 any other or perhaps for all other species in which the phenomenon 

 has been studied. Publications giving data in detail and con- 

 clusions for results obtained previous to 191 7 together with dis- 



