THE FAUNA OF AEGENTINA 897 



of that remarkably fertile country, which has lately become 

 a centre of attraction, not only from a point of view of 

 agriculture, but as a treasure-house of palaeontological 

 records. 



Argentina must have undergone very notable physio- 

 graphical and climatic changes within the Tertiary Era. As 

 Dr. White * has pointed out, the whole of the coast-line from 

 Eio de Janeiro southward appears to present evidences of 

 submergence. Elvers, bays and islands exhibit an aspect 

 of drowning similar to that shown by the rivers and bays of 

 Nova Scotia, Cape Breton and Newfoundland; and the amount 

 of coastal depression seems to increase southward, judging 

 by borings for harbour works at Eio de Janeiro and at 

 Pelotas. 



The presence of terrestrial and fresh-water deposits to a 

 depth of nearly a thousand feet below the city of Bu,enos 

 Aires implies, as Dr. Ameghino f remarks, that here also the 

 continent extended formerly much further eastward. The 

 same author contends, in fact, that the whole of the southern 

 Atlantic is of Tertiary age. I am not prepared to concur in 

 this view, but it can scarcely be doubted that Argentina had 

 in later Tertiary times at any rate a much greater area than 

 at present. 



It is now more than twenty years since Dr. Ameghino first 

 made known to the world that an extraordinary wealth of 

 animal life once tenanted the vast plains of Argentina. Not 

 only in early Tertiary deposits; even in late Mesozoic beds 

 were found the bones of mammals belonging to many different 

 groups. The origin of life, at least of the higher animals, was 

 always looked for in the north. Dr. Ameghino's discoveries, 

 which certainly rank among the most noteworthy that have 

 ever been made in palaeontology, riveted attention for the 

 first time to the southern hemisphere. No wonder that Dr. 

 Ameghino J in his enthusiasm pronounced Argentina to be 

 the original home of all the mammals of the world. 



* White, I. C, " Eelatorio final de estudos das minas," p. 3. 

 t Ameghino, Fl., " Formations sfidimentaires, p. 29. 

 X Ameghino, FL, " South America as the Source of Mammalia," 

 p. 260. 



