400 



C. SKOTTSBERG 



It is very easy to construct a hypothetical passage by which the '^ Coprosma 

 group" reached Juan Fernandez without crossing the Antarctic or encroaching very 

 much upon the surface of the Pacific Ocean. If we have reason to think that South 

 America extended farther west I cannot see why this wasn't the case also with West 

 Patagonia and Tierra del F"uego, a region which undoubtedly has undergone con- 

 siderable submergence; we have to count with a wide Scotia bridge and an exten- 

 sion of Palmer (Graham) Land, where the geographical-geological situation is the 

 same as in South America and where the uplift of the mighty "Antarctandes" 

 ought to have been accompanied by submergence of the fore-land. Plants and 

 animals could have travelled by a circuitous route from the New Zealand region 

 over West Antarctica to Juan Fernandez without finding their way east to what 

 is now Chile. This south Pacific path was suggested above when I tried to divide 

 the angiosperms according to their supposed primary sources; the species involved 

 are enumerated under I: 3, forming a group "as far as known without continental 

 American affinities, either suggesting an ancient Antarcto-Pacific track east from 

 Australasia without reaching America, or having arrived along the road over the 

 Scotia Arc without leaving any traces in the present American flora" (p. 269). 



This idea of a South Pacific track is not new. It was postulated by Arldt 

 as a South Pacific bridge and it finds an expression in Croizat's South Pacific 

 base-line, which, however, if it existed, hardly permits us to draw such far-reaching 

 conclusions as he did. In the case of Juan Fernandez only 13 genera are concerned, 

 belonging to 11 families, the ferns not included, but they make up 20% of the 

 angiosperms, and others may have existed that disappeared later. 



It remains to see if, among the cryptogams, a '^ Coprosnia group" can be 

 recognized. In Herzog's paper on the Hepaticae {^130) a single species is indicated 

 as restricted to New Zealand and Juan Fernandez, PalUnncinia xjp/iouies, and two 

 endemic species are said to have their nearest allies not in South America but 

 in New Zealand. No case equal to Pallavicinia is found among the mosses, but 

 several endemic species are considered to be related, not to American ones, but 

 to species inhabiting the south-west Pacific region. 



With regard to the fauna 1 shall confine myself to some general remarks. 



The few land-birds are of neotropical origin. Of the seven species, three, 

 Eiisteplianus galeritns, the owl and the thrush, occur in identical forms on the 

 mainland; the remainder are either endemic varieties or endemic species. The 

 most divergent is Eustep harms fernandensis. GOETSCll's idea that it originated in 

 the islands as a mutation of E. galeritus is contradicted by the fact that they are 

 not at all closely related but even brought to different genera by some ornitho- 

 logists. The former is a relict, the latter perhaps a late immigrant. Of the breeding 

 sea-birds the genus Pterodrovia forms an austral-circumpolar element and may, in 

 preglacial time, have inhabited the coasts of Antarctica and adjacent islands. 



Little can be said as yet about the invertebrates. The endemic leech, Xcso- 

 p/ijlaonon, is an important case of non-American ancestry, and the only terrestrial 

 amphipod is Dicentric. The spider fauna is an appendix to the fauna of South 

 America, but with special features; there is no endemic genus, but specific endem- 



