326 



C. SKOTTSBERG 



F^inzelheiten einzugehen, aiif der asiatischen Seile des Ozeans zu siichen, der sie jedenfalls 

 in den betrachtcten geologischen Zeitcn erheblich niiher als heute gelegen hal)en miis- 

 sen. Die biologischen Verhaltnisse scheinen dies zu l)estiitigen. So haben nach G rise- 

 bach iind I) rude die Hawaiinseln eine Flora, die am niichsten verwandt nicht mit 

 Nordamerika ist, das ihnen doch am niichsten liegt, und von dem heute Lult- und 

 Meeresstromung herkommen, sondern mit der alten Welt. Die Insel Juan Fernandez 

 zeigt nach Skottsl)erg gar kcine X'erwandtschaft mit der doch so nahen Kiiste von 

 ('hile, sondern mit Feuerhmd, Antarktika, Xeuseehind und den anderen pazifischen 

 Insehi. Doch sei hcrvorgehoben, dass die biologischen Verhaltnisse auf Inseln allge- 

 mein schwerer zu dcuten sintl als diejenigen auf grosseren Landraumen. 



In the 3r(l edition j). 59 we read after "Jnseln": "Dies passt vorziiglich zu unserer 

 Vorstelluni^, class Siidanicrika, nach Westen wandernd, sich ihr erst in letzter 

 Zcit so wcit i^enahert bat, dass der Morenunterschied auffallend wird." In the 

 following editions this sentence was excluded. 



Certainly I never said anything like that and I fail to see where Wegp:ner 

 got bis strange ideas; just as many other writers I have pointed out that the Andean- 

 Chilean element is stronger than any other. F.vcn to a firm believer in the festoon 

 theory the Juan FYTnandez and Desventuradas Islands ought to ofifer insuperable 

 difficulties. \\'K(;i:m:r built his theory on the island arcs accompanying the Asiatic- 

 Australian continental border; geologically these arcs are continental, but when 

 he came to island chains like Hawaii, the Marshall Islands and the Society Islands 

 — and we can add Marquesas, Tuamotu etc. — all of which are situated outside 

 the decj) trenches, neovolcanic and regarded as built up from the depths of 

 the ocean "he was driven to assume that they have a sialic basement hidden 

 under tlie basaltic layers. He thinks that this assumption is supported by pend- 

 ulum observations, the force of gravitation being greater over the islands than 

 over the open ocean where, of course, a sial cover is incompatible with his dis- 

 j^lacement theory. 



\\'K(;i:M.k's theories were taken up by Dr Toil' and presented in a modi- 

 fied form ((S7); I shall (juote his attitude toward the festoons. 



As Wj'.cini.r has observed, they are all comj)arable in size, regular, linked to- 

 gether en (,( helon and convex to the Pacific; each shuts off a large ])ortion of sea and 

 tronts an ex eani< deep, while the concave side bears a row of volcanoes. To Suess we 

 owe the (onception of the deve]oi)ment of successive arcuate asymmetrical fold-waves mi- 

 grating outwards from the more stable "Amphitheatre of Irkutsk", which led to ])rogressive 

 e\i)ansion of .Asia towards the Tac ific. While the hypothesis has since had to be ap- 

 jircc iatcl\ modihef], its fundamental ideas have been brilliantly confirmed by subsequent 

 investigations... Significant are the (x^eanic fossae that immediately front the convex 

 sides of the arcs — foredeeps subsiding in nih'ance of the outward-moving geoantoclines 

 and incidentally tracts ot marked coastal instability (pp. 186-187). 



How tar (lid this outward movement, these advance-folds proceed? Does Du 

 Toil allow all the Pacific island chains to be linked up here? When the great 

 W'NW swing of Asia is rcj)laced by an expansion toward the Pacific, the system 

 of rifts in the ocean floor, oxer which the island chains as claimed by most 

 geologists were formed, did not exist, because there was no tension to account 

 for them; instead, series of ri|>ples were crumpled up on the floor. The transfor- 



