102 Fet'tility in Cichorium intybus 



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

 quite in agreement with this conclusion. 



11. The conditions controlling sex-fusions, ']Mdigedi 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 are of epigenetic 

 and individual development. 



12. The factors which determine or prohibit successful fertilization 

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

 to degree, specificity, and transmission in heredity. 



New York Botanical Garden, 

 Jfai/ 10, 1917. 



EXPLANATION OF PLATES. 



PLATE IV. 



View of series {A x 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 eicperimental plot. Crop of 1916. Several races are shown. 



PLATE VI. 



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

 especially prominent. 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. 



Bauk, E. 1911. Einfiihrung in die experimentelle Vererhungslehre. 



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



odorata." Proc. Cambridge Phil. Soc. x\u}. 

 1913. " Phenomena and problems of self-sterility." Neto Phytologist, 



Vol. XII. pp. 197—206. 

 CoRRENS, C. 1912. " Selbststerilitat und Individiialstoffe." Festschr. d. Med. Nat. 



Oes. z. 84. Versamml. Deutsch. Naturf. u. Arzte. 



*1 



