394 



C. SKOTTSBERG 



Chapter XIII. 



The history of Juan Fernandez — a tentative sketch. 



In my first [)aper on tlie Botany of Juan Fernandez (22/^), where only the 

 vascular plants, as known at that time, were included, I expressed my view on 

 the history of the flora in the following words: 



Frcilich haben wir keine Ahnung davon, wie schnell Arten oder (lattiingen ent" 

 stehen, aber wir konnen uns kaum denkcn, dass in der kurzen Zeit, die seit der Ent" 

 stehung der jetzigen Inseln verHossen ist, sich Typen wie Lactoris oder Rohinsojiia aiis 

 "Keimen" entwickelten, die nach den Inseln gebracht wiirden, um sich in ungestorter 

 Isolierung umzutormcn . . . Ich bin der Meinung, dass das alte Klement nicht auf Masa- 

 ticrra oder Masafucra entstand, sondern alter ist als die jetzigen Inseln, und dass es 

 wenig wahrschcinlich ist, dass die alten, endemischen (oder andere, eng vervvandte) 

 (iattungcn und Arten von Juan Fernandez, noch nachdem die Inseln gebildet waren, 

 die vielen vermeintlichen Ursprungsorte bewohnten, und dass Veriinderungen in der 

 I'flanzenwelt von Polynesian, Neuseeland, Chile u.s.w. in (puirtiirer Zeit die isolierte Stel- 

 lung bewirkt haben. Ich glaube also, dass in vor- und friihtertiarer Zeit grossere Ent- 

 wickelungszentra existierten, und dass ihre Flora nunmehr als ein altpazifischer Rest 

 fortlebt. Auch eine Resttlora wird sich aus vielen Familien und (iattungen aber ver- 

 ba! tnismiissig wenigen Arten zusammensetzen. 



At that time our knowledge of the flora was incomplete; much fresh and new 

 material was added in 19 16-17. I had fixed my attention on what I called the 

 "Old Pacific element", but did not venture to look for an exact site of an evolu- 

 tion centre, though the possibility of Antarctica as an important source of genera 

 and families had been pointed out before; the first sign of the presence of there- 

 tofore unknown, subantarctic flora in Masafuera had been observed, but I had no 

 reason to link it with the Old Pacific types. During the 19 16-17 survey a rather 

 strong Antarctic-bicentric group took shape, and in my 1925 sketch of the history 

 of the flora (.?.?/) not only was this, but also the Old Pacific plants claimed to 

 have "reached Juan F'ernandez over South America, where they have disappeared" 

 (p. 31). My object this time is to see if we can approach these problems in other 

 than general terms. 



Our starting point is the "Tierra de Juan P'ernandez" of BrCckien, forming 

 a westward extension or lobe of South America, reaching the actual site of Juan 

 PY'rnandez and Desventuradas Islands, as indicated by the bathymetrical conditions, 

 something in keeping with the peninsula of Lower California and separated from 

 the coast by a broad, toward the south gradually narrowed bay. However, if we 

 remember that the deep trough is supposed to have originated with the final 

 uj)lift of the Andes, the j)resent coast line ought to be recent all along, but this 

 is not in accordance with the opinion that the P^ocene Arauco flora was a coast 

 flora. The conclusion would be that the great depths were initiated already during 

 Cretaceous times, getting dec|)er and deeper with the successive periods of uplift. 

 The Juan PY'rnandez land or peninsula formed part of the neotropical P2ocene flora 

 region which extended from Venezuela and Brazil to south Chile and east across 

 the mountains, during this era of low relief, as shown by the fossiliferous beds 



