Sechste Sektion: 



Tiergeographie und Palaeon- 



tologie. 



Einführender Vorsitzender : Herr Prof. Dr. R. Hoernes 

 (Graz). Schriftführer: Herr Dr. W. Ben dl (Graz). 



Erste Sitzung. 



Dienstag, den 16. August, Nachmittags 1 / 2 3 Uhr, im allgemeinen 

 Hörsaale des Naturwissenschaftlichen Institutsgebäudes. 



Den Vorsitz führt Herr Prof. Dr. H. E. Crampton (New 

 York City). 



Herr Prof. Dr. H. E. Crampton (New York City) hält 

 seinen angekündigten Vortrag: 



The Principles of Geographica! Distribution as illustrated 

 by Snails of the genus JPartuia inhabiting Southeastern 



Polynesia. 



By Henry E. Crampton (New York City). 



The purpose of the present communication is to offer some 

 of the results of personal explorations and studies in the islands 

 of the South Pacific Ocean, upon the various problems that col- 

 lectively constitute the subject of geographica! distribution. In 

 the course of Statistical studies extending over ten years upon 

 Variation, correlation and inheritance in Lepidofitera a point was 

 reached where it became desirable to undertake a study of some 

 group of inter-related species exhibiting Variation and like pheno- 

 mena, uninfluenced by artificial or laboratory conditions. Follo- 

 wing the advice of Mayer who has done such brilliant work 



