the open plain, and fears neither dog nor man. If a dog
is urged to the attack, its courage is instantly checked by
a few drops of the fetid oil, which brings on violent sickness
and running at the nose. Whatever is once polluted
by it, is for ever useless. Azara says the smell can be
perceived at a league distant; more than once, when entering
the harbour of Monte Video, the wind being off
shore, we have perceived the odour on board the Beagle.
Certain it is, that every animal most willingly makes room
for the Zorillo.
C H A P T E R V.
P,a llia B la n c a — G e o lo g y — E x t in c t q u a d ru p e d s , fo u r E d e n ta ta , h o rse ,
c te n om y s— R e c e n t e x tin c tio n— L o n g e v ity o f sp e cie s— L a rg e a n im a ls do
n o t r e q u ir e lu x u r i a n t v e g e ta tio n— S o u th e rn A f r ic a— S ib e ria n fossils—
C a ta lo g u e o f e x tin c t q u a d ru p e d s in S o u tli A m e ric a— Tw o sp e c ie s o f
O s tric h , h a b its o f— T in o c h o ru s— O v e n -b ird— A rm a d illo e s— V e n om o u s
sn a k e , to a d , liz a rd— P ly b e rn a tio n o f a n im a ls— H a b its o f s e a -p e n— I n d ia n
wars a n d m assa c re s— A r row -h e a d , a n tiq u a r i a n re lic .
1SÍ,
B A H IA B L A N C A .
T h e Beagle arrived on the 24th of August, and a week
afterwards sailed for the Plata. With Captain Fitzroy’s
consent I was left behind, to travel by land to Buenos Ayres.
I will here add some observations, which were made during
this visit, and on a previous occasion, when the Beagle was
employed in surveying the harbour. Not much can be made
out respecting the geology. At the distance of some miles
inland, an escarpment of a great argillaceo-calcareous formation
of rock extends. The space near the coast consists of
plains of hardened mud, and broad bands of sand-dunes,
which present appearances, that can easily be accounted for
by a rise of the land; and of this phenomenon,* although to
a trifling amount, we have other proofs.
At Punta Alta, a low cliff, about twenty feet high, exposes
a mass of partly consolidated shingle, irregularly interstratified
with a reddish muddy clay, and containing numerous
recent shells. We may believe a similar accumulation
would now take place, on any point, where tides and waves
were opposed. In the gravel a considerable number of
bones were embedded. Mr. Owen, who has undertaken the
description of these remains, has not yet examined them
* A few leag u e s fu r th e r s o u th , n e a r th e B a y o f S a n B ia s, M . D ’O rb ig n y
fo u n d g r e a t b e d s o f re c e n t sh e lls e le v a te d b e tw e e n 2 5 a n d 3 0 f e e t a b o v e
tlie lev e l o f th e se a.— Vol. ii., p. 43.