17() GÖTE TLRKSSÜN 



side of i(liohi(tl(H/y (Gams, 1918; here used to denote the science per- 

 taining to the individual organism) and biosociology (Di- Hietz, 1921). 



LITERATURE CITED. 



1. Du RiETZ, G. E.; Fiui:s, Th. C. E.; Osvald, H.; Tkngwali,. a. 1920. Gesetze der 



Konstitution natürlicher Pflanzengesellscluilten. Upsala and Stockholm. 



2. Du I\iKTZ, G. E. 1921. Zur methodologischen Grundlage der modernen Pflanzen- 



soziologie. Upsala. 



3. Gams, H. 1918. Principicnfrage der Vegetationsforschung. Ein Beitrag zur 



Begriffsklärung und Methodik der Biocoenologie. Vierteljahrschr. Naturforsch. 

 Gesellsch. in Zürich, 63. 



4. Hagedoorn, A. L. and A. C. 1921. The relative value of processes causing evolu- 



tion. The Hague. 



5. LoTSY, J. P. 1916. Evolution by means of hybridization. The Hague. 



6. — 1922. Current theories of evolution. Genetica, Deel 4. 



7. TuRESSON, G. 1922 a. The species and the variety as ecological units. Hereditas, 



Bd. III. 



8. — 1922 b. The genotypical response of the plant species to the habitat. Here- 



ditas, Bd. HI. 



