s only about sixty
yards wide; generally it must be nearly double that width. Its
course is very tortuous, being marked by willow-trees and beds of
reeds: in a direct line the distance to the mouth of the river is
said to be nine leagues, but by water twenty-five. We were delayed
crossing in the canoe by some immense troops of mares, which were
swimming the river in order to follow a division of troops into the
interior. A more ludicrous spectacle I never beheld than the
hundreds and hundreds of heads, all directed one way, with pointed
ears and distended snorting nostrils, appearing just above the
water like a great shoal of some amphibious animal. Mare's flesh is
the only food which the soldiers have when on an expedition. This
gives them a great facility of movement; for the distance to which
horses can be driven over these plains is quite surprising: I have
been assured that an unloaded horse can travel a hundred miles a
day for many days successively.

The encampment of General Rosas was close to the river. It
consisted of a square formed by waggons, artillery, straw huts,
etc. The soldiers were nearly all cavalry; and I should think such
a villainous, banditti-like army was never before collected
together. The greater number of men were of a mixed breed, between
Negro, Indian, and Spaniard. I know not the reason, but men of such
origin seldom have a good expression of countenance. I called on
the Secretary to show my passport. He began to cross-question me in
the most dignified and mysterious manner. By good luck I had a
letter of recommendation from the government of Buenos Ayres to the
commandant of Patagones. (4/5. I am bound to express, in the
strongest terms, my obligation to the government of Buenos Ayres
for the obliging manner in which passports to all parts of the
country were given me, as naturalist of the "Beagle.") This was
taken to General Rosas, who sent me a very obliging message; and
the Secretary returned all smiles and graciousness. We took up our
residence in the rancho, or hovel, of a curious old Spaniard, who
had served with Napoleon in the expedition against Russia.

We stayed two days at the Colorado; I had little to do, for the
surrounding country was a swamp, which in summer (December), when
the snow melts on the Cordillera, is overflowed by the river. My
chief amusement was watching the Indian families as they came to
buy little articles at the rancho where we stayed. It was supposed