It
appears, therefore, that these arrow-heads are antiquarian [22]
relics of the Indians, before the great change in habits
consequent on the introduction of the horse into South
America.
[1] Since this was written, M. Alcide d'Orbingy has examined
these shells, and pronounces them all to be recent.
[2] M. Aug. Bravard has described, in a Spanish work
('Observaciones Geologicas,' 1857), this district, and he
believes that the bones of the extinct mammals were washed
out of the underlying Pampean deposit, and subsequently became
embedded with the still existing shells; but I am not convinced
by his remarks. M. Bravard believes that the whole enormous
Pampean deposit is a sub-aerial formation, like sand-dunes: this
seems to me to be an untenable doctrine.
[3] Principles of Geology, vol. iv. p. 40.
[4] This theory was first developed in the Zoology of the
Voyage of the Beagle, and subsequently in Professor Owen's
Memoir on Mylodon robustus.
[5] I mean this to exclude the total amount which may have been
successively produced and consumed during a given period.
[6] Travels in the Interior of South Africa, vol. ii. p. 207
[7] The elephant which was killed at Exeter Change was
estimated (being partly weighed) at five tons and a half.
The elephant actress, as I was informed, weighed one ton less;
so that we may take five as the average of a full-grown
elephant. I was told at the Surry Gardens, that a hippopotamus
which was sent to England cut up into pieces was estimated at
three tons and a half; we will call it three. From these
premises we may give three tons and a half to each of the five
rhinoceroses; perhaps a ton to the giraffe, and half to the
bos caffer as well as to the elan (a large ox weighs from
1200 to 1500 pounds). This will give an average (from the above
estimates) of 2.7 of a ton for the ten largest herbivorous
animals of Southern Africa. In South America, allowing 1200
pounds for the two tapirs together, 550 for the guanaco and
vicuna, 500 for three deer, 300 for the capybara, peccari, and
a monkey, we shall have an average of 250 pounds, which I
believe is overstating the result. The ratio will therefore
be as 6048 to 250, or 24 to 1, for the ten largest animals
from the two continents.
[8] If we suppose the case of the discovery of a skeleton of
a Greenland whale in a fossil state, not a single cetaceous
animal being known to exist, what naturalist would have ventured
conjecture on the possibility of a carcass so gigantic being
supported on the minute crustacea and mollusca living in the
frozen seas of the extreme North?
