DERIVATION OF THE FLORA AND FAUNA 393 



troublesome anomalies and exceptions in the evidence, but none of these can be ade- 

 quately explained by postulating an Antarctic connection. The general weight of evi- 

 dence is against such a connection. 



In scientific theory the best-supported and most nearly self-sufficient hypothesis 

 should be preferred and unnecessary additional hypotheses should be rejected or held 

 in abeyance. On this basis the Antarctic migration route hypothesis remains simply a 

 hypothesis with no proper place in scientific thinking. 



To this I shall make a few remarks. If Simpson had said "no fact involving 

 the vertebrates" instead of "no biotic fact" — very well, let us assume that the 

 routes across from and to either America or New Zealand were impassable to 

 mammals, reptiles, amphibia and flightless land-birds, birds with good flight capa- 

 city would have found little difficulty to cross, and many biotic facts are known 

 that clearly speak in favour of an Antafctic migration route for invertebrates and 

 plants. Simpson must have thought that either did the Antarctic continent never 

 possess a fauna of land vertebrates, or, if it did have one, it had evolved inde- 

 pendently of all other faunas and disappeared without leaving a single trace. 

 Only penguins are known in a fossil state in Antarctic Tertiary deposits. Until 

 fossil land vertebrates are discovered, the question of the former existence of an 

 Antarctic fauna of terrestrial vertebrates must be left open. 



Among the invertebrates are many examples of a discontinuous distribution 

 most readily understood if Antarctica is taken into account. Several were men- 

 tioned in the chapter devoted to the composition of the fauna of Juan Fernandez, 

 a few more may be quoted here. Berland, dealing with the Pacific spider fauna (2j): 



Nous avons tire de notre etude cette notion importante que la liaison entre I'Aus- 

 tralie et I'Amerique a eu lieu par une terre antarctique dont les temoins restent ac- 

 tuellement, mais ni par la Nouvelle Caledonie, ni par la Nouvelle Zelande, ni par le 

 groupe Samoa-Tonga-Fiji, et, par voie de consequence, qu'elle n'a pas eu lieu par le 

 centre du Pacifique (p. 1053), 



Berlioz (2^), with examples off'ered by the distribution and affinities of beetles, 

 states that the group of Buprestidae, forming "le noyau essentiel" in the Bupres- 

 tid fauna of Australia, has mainly South American affinities (several genera), 

 and that 



la faune des Lucanides d'Australie et de Papouasie presente avec celles de I'Amerique 

 du Sud surtout de la region andine et patagonienne, des affinites aussi etroites que 

 curieuses. 



Finally Lindsay (idy), calling attention to the Subantarctic Collembola, 

 extremely delicate creatures "supposed not to be carried any appreciable distance 

 either by wind or sea, thus being important proofs of former land connections", 

 mentions a genus of 3 species of which one is Fuegian, one recorded from 

 the Scotia Arc, and one found in New Zealand. And other similar examples may 

 be found. 



