THE GALLS OF THE ISLANDS OF THE KRAKATAU-GROUP 

 AND OF THE ISLAND OF SEBESY 



by 



W. DOCTERS VAN LEEUWEN 

 (Buitenzorg). 



Introduction. 



Iii a previous article ') the new gall-flora of Krakatau was discussed 

 by me. The reader may be assumed to be aware that in 1883 Krakatau 

 was completely devastated, stripped of ail animal and vegetable life, and 

 it was therefore worth while investigating to wliat extent the galls had 

 also got back to this island after the new flora had been formed. Not 

 only Krakatau was ravaged by this éruption, ail the islands in the Sunda 

 Strait and the adjacent coasts of Sumatra and Java suffered more or less. 

 The island of Sebesy, situated at only IQ miles' distance from Krakatau 

 (see the map on table 1) was hit hardest. But the dévastation had not 

 gone so far as that of the islands of the Krakatau group. 



During the excursions which were made on the island of Sebesy for 

 the purpose of becoming acquainted with the new flora, I had also op- 

 portunities of coUecting galls, though attention could not be devoted 

 exclusively to this subject. Although the végétation was probably not 

 entirely destroyed, and has been partially restored from rhizomes, tree- 

 stumps and seeds, we may assume that the galls had disappeared alto- 

 gether from the island and could not return there until after a considérable 

 lapse of time, seeing that hardly any plants were présent on the island 

 during the first year. As the flora was soon far richer than that on the 

 far more intensely ruined Krakatau, the chances for the récupération of 

 the gall-flora were greater, and I accordingly found on Sebesy a number 

 of varieties not yet occurring on Krakatau, and which indeed could not 

 occur there because the plants on which the galls grow had not yet 

 reached the islands of the Krakatau-group. 



On Krakatau and Verlaten Eiland 1 made several more trips after my 

 first visit in April 1919 and the number of galls now found by me already 

 amount to 44, which is indeed a large number, when one considers that 

 the flora is as yet very poor in the number of différent species of plants, 

 and that the gall-producing créatures had to be conveyed over so great a 



') W. DoCTERS VAN Leeuwen. The galls of "Krakatau" and "Verlaten Eiland' 

 (Désert Island) in 1919. Annales du Jard. Bot. Buitenzorg. Vol. XXXI. 1920. p. 57. 



