VON Jhering. — Oil the Ancient Connections of N.Z. 441 



tinent a higlier age. The relative sentence runs as follows : 

 " The recent Australian Diprotodonta therefore must date back 

 in this continent as far as the beginning of the Eocene period 

 at least, whilst the ancestors of the Diprotodonta common to 

 Australia and Argentina must reach to a far more remote 

 epoch, during which they were spreading over a very wide 

 continent unitjng Australia with South America in a more or 

 less continuous connection." Ameghino thinks this continent 

 was situated in the Pacific Ocean, and dated back to the Trias 

 formation. 



It is evident that these results must alter in many respects 

 the hitherto-prevailing ideas. The theory mentioned by Pro- 

 fessor Hutton, which allowed a Tertiary migration of northern 

 types over the Andes into the Antarctic area, fails, for during 

 the Cretaceous and in the beginning of the Tertiary era there 

 was no chain of the Andes existent''' ; and when it began to rise, 

 though to no considerable elevation, it was covered with a 

 tropical, not alpine, flora. The reasons given allow much less 

 an immigration of northern plants from North America over 

 the whole length of the Andes. So far as an exchange of 

 plants between Australia, &c., and South America took place, 

 it must have gone on over the same land-bridge on which, in 

 other latitudes or at other times, the temporary migration of 

 the Antarctic flora went on. Whether such a rigorous distinc- 

 tion between a South American and an Antarctic flora as has 

 been hitherto made will be possible to the same extent in 

 future, seems to me very doubtful. Those who do not agree 

 with me herein must indeed first study the phytogeographical 

 condition of Eio Grande do Sul, especially the southern part 

 of it, where, besides plants common in Argentina and 

 Uruguay, many of central Brazil are found also : thus Cedrela, 

 Erythroxylon, Tecoma, Erytliriiut, &c., with Sentio, DiLvana, 

 Celtis, Jodina, Phyllanthus, Lacmna, &c., even the Pata- 

 gonian Bcrberis sjnnescens, and, as I believe, CoUetia also. 



It therefore follows that the relations of the South American 

 to other fauna-areas, as I have represented it here, are in strong 

 opposition to Mr. Wallace's views ; but, with regard to its 

 relations to xVustralia and New Zealand (though variously 

 modified in respect of South America), it is in harmony with 

 the theory at which Professor Hutton, and other scientists 

 who have studied the flora and fauna of the Australian region, 

 have arrived. 



To conclude, the results arrived at may be summed up as 

 follows : South America was separated from North America 

 from the Cretaceous to the end of the Pliocene period. A 



* I suppose this migration to have taken place in the Phocene. 

 — F.W.H. 



