84 



Treubia Vol. Ill, i 



This high percentage proves, I think, that flight or sailing on the wind plays 

 an important part in the re-population of the islands by animals. 



It is true that many insects may have reached the islands not on the wing, 

 but on drifting wood or plants in the form of egg, larva or pupa. However, 

 I believe we must attribute a greater share to the dispersal by air than 

 is usually done, for let us see how many wingless animals there are on 

 the islands? 



We find a percentage of 19, 17 and 21 resp. for Krakatau, Verlaten I. 

 and Sebesy. 



List of wingless animals» 





1908 







1921 







_; 







^ 





,—i 



^ 





■—1 



* 



a 



n 





3 



c 





a 



<u 



> 



TO 



<u 



> 





a 



+ 



TO 



TO 



+ 



TO 



>-> 





TO 



u. 





k> 



<u 



u, 



ba 



&> 



v^ 



^ 



> 



^ 



^ 



> 



^ 



CA) 



CO 



Muridae . . . . 



Reptilia .... 



Insecta .... 

 Mutillidae ($Ç) 

 Psychidae (ÇÇ) 

 Coccidae ($Ç) 

 Blattidae ($Ç) 

 Rhaphidophora 

 Aptera . . . 



Myriapoda . . . 



Arachnida . . . 

 Araneae . . 



Crustacea . . . 



Mollusca .... 



Vermes .... 















1 







1 



2 







2 



4 



5 



6 



6 







6 



11 



10 



18 















2 



1 



2 



3 







3 



1 



3 



3 



1 







1 



5 



6 



10 



1? 







1? 



1 







1 























1 



1 







1 



2 







2 



6 







6 



4 



1 



4 



18 







18 



73 



37 



82 



15 







15 



45 



21 



52 1 



3 







3 



3 



2 



5 



2 







2 



5 



3 



5 



1 







1 



6 







6 



2 

 7 



11 

 1 

 1 

 4 

 1 

 3 

 1 

 9 



82 



48 

 4 



10 

 6 



Total 



38 







38 



107 



58 



127 



131 



The agent for the dispersal of all these animals need not be ocean 

 currents only ; many among them may have come to the islands by other means. 



In the first place, rats were certainly brought to their new habitat by man. 

 Of the Reptiles, Python and Varanus are probably quite able to swim over the 

 distance separating Krakatau or Verlaten I. from Sebesy or other islands in the 

 neighbourhood. Both reptiles, if pursued, get easily out to sea and swim with 

 great agility. JACOBSON noticed during his visit also a Varanus swimming 

 alongside the ship. Pythons seem to cover long distances when in need of food. 



