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Andian and Brazilian Araucarias, are restricted to a 

 small region in the southern hemisphere, was one of 

 the most widely spread sections of the seed-bearing 

 plants during the Mesozoic era. Ancestors of Arau- 

 caria must have been common trees in the European 

 vegetation in Jurassic and Lower Cretaceous periods, 

 and even as late as the Tertiary period there is evidence 

 that representatives of the family still lingered in 

 the north. One conclusion which seems almost un- 

 avoidable is that the species of Araucaria and Agathis 

 that survive, in some cases only in one or two small 

 islands in the South Pacific, have in the course of 

 successive ages wandered from the other end of the 

 world. Their migrations can be partially traced by 

 the fragments embedded in Jurassic and later sedi- 

 ments, but we can only speculate as to the causes 

 which have contributed to the changes in the fortunes 

 of the family ; how much influence may have been 

 exerted by changes in physical conditions in the 

 environment, and to what extent the production of 

 more successful types may have been the dominant 

 cause of the decline, it is impossible to say. One 

 thing at least is certain, that few existing plants are 

 better entitled to veneration as survivals from the 

 past than are the living species of Araucaria. 



