20 
NOTICE OF THE MEGATHERIUM. 
and rolled ; while to others, barnacles, serpulse and corallines were attached in the long period 
which elapsed before they were entirely covered by the mad. But the largest number of 
them are quite uninjured, and retain all their minutest prominences perfectly preserved, show- 
ing that they were protected by flesh or ligaments while being buried. The parts of the 
great Scelidothefium discovered in the same deposit by Darwin were all found lying in their 
proper relative position, even to such small bones as the knee-cap. The great abundance of 
these remains of land animals lead us to look upon some large areas of these Pampas as estu- 
ary deposits. We may suppose that ages ago great bays of the ocean occupied these areas.. 
That into these bays the vast tributaries of the Plata brought down the carcasses of the 
gigantic Mammals, and there, acted upon by currents, they drifted to the points where sand 
and shingle were accumulating in shoals. The only physical change since that time has been 
a gradual rising of the continent. Once buried, no cataclysm has disturbed their quiet rest. 
The North American species of the Megatherium lived in the same pleistocene period. Skid- 
daway island — an upper tertiary formation, consists of flat sandy banks rising but a few feet 
above the level of high tide, — and overyling beds containing marine shells belonging to' 
forty-five species now inhabiting the neighboring sea. 
It is interesting to consider the condition of our western continent at an age so immediately 
antecedent to the introduction of Man. The contour of the coast lines was already defined, 
and the external features of the country were nearly the same which they now are. The 
lofty Andes had just been lifted up, and taken their place among the mountain ranges of our 
globe. Their newly made slopes were already furrowed by the same water courses which now 
feed the mighty La Plata, and the vegetation of the then more restricted Pampas differed 
little from that- at present characteristic of them. Forest trees were dotted about at intervals, 
and fringed the banks of rivers and lagunes ; but as a whole, the vast plain, as now, was 
“ Barren and bare, unsightly, unadorned.” 
The statement that a giant race of leaf-eating quadrupeds then roamed these plains need not 
too seriously try our faith. For a survey of living nature shows that no close relation exists 
between the bulk of the animal species and the quantity of the vegetation, in the countries 
where the Mammalia abound. The Camel, an animal of no mean size, has lived, and found 
its sustenance, for ages, on the sterile desert. South Africa, with its scanty vegetation (ten 
times less than that of Great Britain) supports larger herbivorous quadrupeds than luxuriant 
South America. We owe this latter statement to Mr. Darwin, who says further that the 
average weight of the ten largest animals in the former country is 6,048 pounds, while in South 
America it is but 250 pounds, — a ratio of 24 to 1 in favor of the dry African plain with its 
sparsely scattered shrubs. The number of animals which lived on or near the early Brazilian 
Pampas is surprisingly great. Darwin found no less than nine huge skeletons at Punta Alta 
within a space of about 200 yards square. He says, moreover, that a trench could probably 
not be cut across these plains in any direction without intersecting and laying bare some of 
their remains.* 
* The manner in which this vast sepulchre of extinct quadrupeds has received its burden is one of the first 
questions which then*. contemplation suggests. We are disposed to accept Mr. Darwin’s view concerning the 
physical conditions under which the Pampas were formed, and we readily conceive of the immense freight of 
