DERIVATION OF THE FLORA AND FAUNA 395 



of Pichileufu. As the Concepcion-Arauco flora it was a subtropical rain forest 

 flora with podocarps, tree ferns, evergreen dicotyledonous trees and Hanas, be- 

 longing to some 30 tropical families; the species were, with two exceptions, referred 

 bv Berry to still existing genera — if the determinations are reliable. This is 

 perhaps more than wc can expect; all we can sa}' is that Bekrv was a man with 

 a wide experience of both fossil and living tropical plants and that undoubtedly 

 many of the families listed and perhaps also a fair number of the genera are 

 correctly placed. Two are found in the present flora of Juan Fernandez. To Aza?a 

 celastriniforDiis and tertiaria — and the fossil does suggest Azara — Rerrv remarks 

 {28. 107): 



As a recent form occurs on the island of Juan Fernandez one can predicate a con- 

 siderable antiquity for the genus, which is more than verified by the present fossil forms. 



His Berheris cory))ihos7Jlora is of still greater interest: 



I have seen leaves of all the South American species and the most similar is Berberis 

 iorymlwsa Hook, et Arn. of Juan Fernandez (i.e. 75). 



I have compared his illustrations with the island species and I am willing to 

 testify to the striking similarity between them. A revision of these most important 

 fossil floras, with application of modern technique, is eagerly longed for. 



Anyhow, the neotropical character of the old flora has been safely estab- 

 lished, and Arauco and Pichileufu agree in their general composition; 20 species 

 occur in both. If this flora extended to Juan Fernandez, this land must have been 

 sufficiently high to force the prevailing westerly winds to unload part of their 

 moisture and to give rise to altitudinal belts. The flora most likely had its special 

 distinctive marks. In view of the very large area it inhabits, it cannot have been 

 uniform, and difterent floristic provinces showed special features and had their 

 own endemics. If anything still survives in identical or very similar form can only 

 be a subject of conjecture and is not demionstrated by leaf impressions. Two of 

 the genera reported from the mainland, Acara and Myrceugenia, still occur in 

 Chile and Juan Fernandez, and I am inclined to believe that the endemic element 

 in the insular forest flora dates back to early Tertiary times, genera like Podo- 

 phorus, Megalachne, Jiiania, Ochagavia, Xothomyrcia and Selkirkia, and species 

 of Chusguea, Hesperogreigia, Urtica, Phrygilaiithus, Chenopodiiim, Colletia, Dys- 

 cpsis, Vgni, Erytigium, RJiapJiithaninus, SolajiiDii and Xicotiana. 



Centaurode)id)'on, Yiaiquea and the four endemic Cichoriaceous genera stand 

 apart. They are montane and we have no clue at all to their histor}', but we can 

 take it for granted that they are not ''new beginners", but old relicts, without 

 any near relatives anywhere. Whether we assume that they arose in the islands 

 and have left no marks in the continent, or derive the four dendroseroid genera, 

 which form a natural group, from Antarctic ancestors, a possibility certainly not 

 offered by Ceiitaia-odendron and Yunquea, we are victims of wild speculation. 



Few endemic ferns belong to the neotropical element, Triclionianes Ingae, 

 Dryopteris inacqtialifolia, Asplenium macrosorum and stellaium, Pellaea chiiensis. 



