THE FAUNA OF ARGENTINA 
397 
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 
13r. White * has pointed out, the whole of the coast-line from 
Rio de Janeiro southward appears to present evidences of 
submergence. Rivers, 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 Rio 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 Buenos 
Aires implies, as Hr. 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 Hr. 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. Hr. 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 Hr. 
Ameghino J in his enthusiasm pronounced Argentina to be 
the original home of all the mammals of the world. 
* White, I. C., “Relatorio final de estudos das minas,” p. 3. 
f Ameghino, Ft, “ Formations sedimentaires, p. 29. 
f Ameghino, FI., “South America as the Source of Mammalia,” 
p. 260. 
