10*2 Fertilitjj in Cichorium intybus 



at hand lor the behaviour of similar phenomena in other species is also 

 quite in agreement with this conclusion. 



11. The conditions controlling sex-fusions, ]\\dged. by the behaviour 

 of compatibilities and incompatibilities in such species as Cichorium 

 Intybus, arise in connection with the development of the sex organs and 

 sex cells as such. In this sense the controlling factors arc of epigenctic 

 and individual development. 



12. The factors which determine or prohibit successful fertilization 

 in. chicory, tvhatever their essential nature may be, are highly variable as 

 to degree, specificity, and transmission in heredity. 



New York Botanical Garden, 

 May 10, 191J. 



EXPLANATION OF PLATES. 



PLATE IV. 



View of series (A y. E22)-10-13- of the semi-dwarf bushy race showing very decided 

 uniformity in general vegetative habit. Ten of this series were self-sterile and six 

 were self-fertile. In the foreground is a plant of series (A x E22)-10-8- showing a 

 tall sparsely branched habit of growth. These plants are from two generations of 

 self-fertile ancestry. 



PLATE V. 



View of chicory in experimental plot. Crop of 1910. Several races are shown. 



PLATE VL 



Another view in experimental plot. Crop of 1916. Dwarf and semi-dwarf races are 

 especially promioent. Plants shown in Plates V and VI are from three generations 

 of self-fertile ancestry. Plants here shown were self-compatible or self-incompatible 

 quite indiscriminately. 



BIBLIOGRAPHY. 



BaUR, E. 1911. Einfiihrani) in die cxpcrimctitelle Vcrerhungslehre. 



CoMPTON, R. H. 1912. "Preliminary note on the inheritance of sterility \n Reseda 



odorata." Proc. Gnmhridge Phil. Soc. xviii. 

 1913. " Phenomena and problems of sclf-.sterility." A^exo Phytologist, 



Vol. XII. pp. 197—206. 

 CoRREKS, C. 1912. " Selbststerilitat und Individualstoffe." Festsclir. d. Med. Nat. 



Ges. z. 84. Versamnd. Deutsch. Naturf. v.. Arzte. 



