darwin's voyage

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Devonport, England

12/27/1831 - 1/16/1832

Her Majesty's ship Beagle, under the command of Captain Fitz Roy, R.N., sailed from Devonport on the 27th
of December, 1831. The object of the expedition was to complete the survey of Patagonia and
Tierra del Fuego, commenced under Captain King in 1826 to 1830 -- to survey the shores of
Chile, Peru, and of some islands in the Pacific. On the 6th of January we reached Teneriffe, but were prevented
landing, by fears of our bringing the cholera. On the 16th of January, 1832, we anchored at Porto Praya, in St. Jago, the
chief island of the Cape de Verd archipelago.

Rio de Janeiro, Brazil

1/16/1832 - 7/5/1832

In the morning we got under way, and stood out of the splendid harbour of
Rio de Janeiro. As soon as we entered the estuary of the Plata, the weather was
very unsettled. The sea was so highly luminous, that the tracks of the
penguins were marked by a fiery wake, and the darkness of the sky was momentarily illuminat-
ed by the most vivid lightning.

Maldonado, Uruguay

7/24/1832 - 8/24/1833

The Beagle sailed from Maldonado, and on August the 3rd she arrived off
the mouth of the Rio Negro. This is the principal river on the whole line of coast between the
Strait of Magellan and the Plata. About fifty years ago, under the old Spanish government, a small colony was
established here; and it is still the most southern position on this eastern coast of
America, inhabited by civilized man.

Buenos Aires, Argentina

August 24, 1833 - January 9, 1834

The Beagle arrived a week afterwards sailed for the Plata. With
Captain Fitz Roy'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.

The plain, at the distance of a few miles from the coast, belongs to the great Pampean forma-
tion, which consists in part of a reddish clay, and in part of a highly calcareous marly rock.
Nearer the coast there are some plains formed from the wreck of the upper plain, and from
mud, gravel, and sand thrown up by the sea during the slow elevation of the land, of which ele-
vation we have evidence in upraised beds of recent shells, and in rounded pebbles of pumice
scattered over the country. At Punta Alta we have a section of one of these later-formed little
plains, which is highly interesting from the number and extraordinary character of the remains of gigantic land-animals embedded in it. These have been fully described by Professor Owen, in
the Zoology of the voyage of the Beagle, and are deposited in the College of Surgeons. I will
here give only a brief outline of their nature.

First, parts of three heads and other bones of the Megatherium, the huge dimensions of which
are expressed by its name. Secondly, the Megalonyx, a great allied animal. Thirdly, the
Scelidotherium, also an allied animal, of which I obtained a nearly perfect skeleton. It must
have been as large as a rhinoceros: in the structure of its head it comes, according to Mr. Owen,
nearest to the Cape Anteater, but in some other respects it approaches to the armadilloes.
Fourthly, the Mylodon Darwinii, a closely related genus of little inferior size. Fifthly, another
gigantic edental quadruped. Sixthly, a large animal, with an osseous coat in compartments, very
like that of an armadillo. Seventhly, an extinct kind of horse, to which I shall have again to
refer. Eighthly, a tooth of a Pachydermatous animal, probably the same with the Macrauchenia,
a huge beast with a long neck like a camel, which I shall also refer to again. Lastly, the
Toxodon, perhaps one of the strangest animals ever discovered: in size it equalled an elephant
or megatherium, but the structure of its teeth, as Mr. Owen states, proves indisputably that it
was intimately related to the Gnawers, the order which, at the present day, includes most of the
smallest quadrupeds: in many details it is allied to the Pachydermata: judging from the position
of its eyes, ears, and nostrils, it was probably aquatic, like the Dugong and Manatee, to which it
is also allied. How wonderfully are the different Orders, at the present time so well separated,
blended together in different points of the structure of the Toxodon!

The remains of these nine great quadrupeds, and many detached bones, were found embedded
on the beach, within the space of about 200 yards square. It is a remarkable circumstance that
so many different species should be found together; and it proves how numerous in kind the
ancient inhabitants of this country must have been. At the distance of about thirty miles from
Punta Alta, in a cliff of red earth, I found several fragments of bones, some of large size.
Among them were the teeth of a gnawer, equalling in size and closely resembling those of the
Capybara, whose habits have been described; and therefore, probably, an aquatic animal. There
was also part of the head of a Ctenomys; the species being different from the Tucutuco, but
with a close general resemblance. The red earth, like that of the Pampas, in which these remains
were embedded, contains, according to Professor Ehrenberg, eight fresh-water and one salt-water infusorial animalcule; therefore, probably, it was an estuary deposit. The remains at Punta Alta were embedded in stratified gravel and reddish mud, just such as the
sea might now wash up on a shallow bank. They were associated with twenty-three species of
shells, of which thirteen are recent and four others very closely related to recent forms. From
the bones of the Scelidotherium, including even the knee-cap, being intombed in their proper
relative positions, and from the osseous armour of the great armadillo-like animal being so well
preserved, together with the bones of one of its legs, we may feel assured that these remains
were fresh and united by their ligaments, when deposited in the gravel together with the shells.
Hence we have good evidence that the above enumerated gigantic quadrupeds, more different
from those of the present day than the oldest of the tertiary quadrupeds of Europe, lived whilst. the sea was peopled with most of its present inhabitants; and we have confirmed that remark-
able law so often insisted on by Mr. Lyell, namely, that the "longevity of the species in the
mammalia is upon the whole inferior to that of the testacea."

Port St. Julian, Argentina

January 9, 1834 - January 15, 1835

Everything in this southern continent has been effected on a grand scale: the land, from the Rio
Plata to Tierra del Fuego, a distance of 1200 miles, has been raised in mass (and in Patagonia to
a height of between 300 and 400 feet), within the period of the now existing sea-shells. The old
and weathered shells left on the surface of the upraised plain still partially retain their colours.
The uprising movement has been interrupted by at least eight long periods of rest, during which
the sea ate deeply back into the land, forming at successive levels the long lines of cliffs, or
escarpments, which separate the different plains as they rise like steps one behind the other. The
elevatory movement, and the eating-back power of the sea during the periods of rest, have been
equable over long lines of coast; for I was astonished to find that the step-like plains stand at
nearly corresponding heights at far distant points. The lowest plain is 90 feet high; and the
highest which I ascended near the coast, is 950 feet; and of this, only relics are left in the form
of flat gravel-capped hills. The upper plain of Santa Cruz slopes up to a height of 3000 feet at
the foot of the Cordillera. I have said that within the period of existing sea-shells, Patagonia has
been upraised 300 to 400 feet: I may add, that within the period when icebergs transported
boulders over the upper plain of Santa Cruz, the elevation has been at least 1500 feet. Nor has
Patagonia been affected only by upward movements: the extinct tertiary shells from Port St.
Julian and Santa Cruz cannot have lived, according to Professor E. Forbes, in a greater depth of
water than from 40 to 250 feet; but they are now covered with sea-deposited strata from 800 to
1000 feet in thickness: hence the bed of the sea, on which these shells once lived, must have
sunk downwards several hundred feet, to allow of the accumulation of the superincumbent stra-
ta. What a history of geological changes does the simply-constructed coast of Patagonia reveal!

Bay of S. Carlos, Chile

January 15, 1835 - February 20, 1835

we sailed from Low's Harbour, and three days afterwards anchored a sec-
ond time in the bay of S. Carlos in Chiloe. On the night of the 19th the volcano of Osorno was
in action. At midnight the sentry observed something like a large star, which gradually
increased in size till about three o'clock, when it presented a very magnificent spectacle. By the
aid of a glass, dark objects, in constant succession, were seen, in the midst of a great glare of
red light, to be thrown up and to fall down. The light was sufficient to cast on the water a long
bright reflection. Large masses of molten matter seem very commonly to be cast out of the
craters in this part of the Cordillera. I was assured that when the Corcovado is in eruption, great
masses are projected upwards and are seen to burst in the air, assuming many fantastical forms,
such as trees: their size must be immense, for they can be distinguished from the high land
behind S. Carlos, which is no less than ninety-three miles from the Corcovado. In the morning
the volcano became tranquil….

Valdivia, Chile

February 20, 1835 - March 4, 1835

This day has been memorable in the annals of Valdivia, for the most severe
earthquake experienced by the oldest inhabitant. I happened to be on shore, and was lying down
in the wood to rest myself. It came on suddenly, and lasted two minutes, but the time appeared
much longer. The rocking of the ground was very sensible. The undulation appeared to my
companion and myself to come from due east, whilst others thought they proceeded from south-
west: this shows how difficult it sometimes is to perceive the directions of the vibrations. There
was no difficulty in standing upright, but the motion made me almost giddy: it was something
like the movement of a vessel in a little cross-ripple, or still more like that felt by a person skat-
ing over thin ice, which bends under the weight of his body.A bad earthquake at once destroys
our oldest associations: the earth, the very emblem of solidity, has moved beneath our feet like
a thin crust over a fluid; -- one second of time has created in the mind a strange idea of insecu-
rity, which hours of reflection would not have produced. In the forest, as a breeze moved the
trees, I felt only the earth tremble, but saw no other effect. Captain Fitz Roy and some officers
were at the town during the shock, and there the scene was more striking; for although the
houses, from being built of wood, did not fall, they were violently shaken, and the boards
creaked and rattled together. The people rushed out of doors in the greatest alarm. It is these
accompaniments that create that perfect horror of earthquakes, experienced by all who have
thus seen, as well as felt, their effects. Within the forest it was a deeply interesting, but by no
means an awe-exciting phenomenon. The tides were very curiously affected. The great shock
took place at the time of low water; and an old woman who was on the beach told me that the
water flowed very quickly, but not in great waves, to high-water mark, and then as quickly
returned to its proper level; this was also evident by the line of wet sand. The same kind of
quick but quiet movement in the tide happened a few years since at Chiloe, during a slight
earthquake, and created much causeless alarm. In the course of the evening there were many
weaker shocks, which seemed to produce in the harbour the most complicated currents, and
some of great strength.

Concepción, Chile

March 4, 1835 - September 15, 1835

We entered the harbour of Concepcion. While the ship was beating up to the
anchorage, I landed on the island of Quiriquina. The mayor-domo of the estate quickly rode
down to tell me the terrible news of the great earthquake of the 20th: -- "That not a house in
Concepcion or Talcahuano (the port) was standing; that seventy villages were destroyed; and
that a great wave had almost washed away the ruins of Talcahuano." Of this latter statement I
soon saw abundant proofs -- the whole coast being strewed over with timber and furniture as if
a thousand ships had been wrecked. Besides chairs, tables, book-shelves, etc., in great numbers,
there were several roofs of cottages, which had been transported almost whole. The storehouses
at Talcahuano had been burst open, and great bags of cotton, yerba, and other valuable mer-
chandise were scattered on the shore. During my walk round the island, I observed that numer-
ous fragments of rock, which, from the marine productions adhering to them, must recently
have been lying in deep water, had been cast up high on the beach; one of these was six feet
long, three broad, and two thick. The island itself as plainly showed the overwhelming power of the earthquake, as the beach did
that of the consequent great wave. The ground in many parts was fissured in north and south
lines, perhaps caused by the yielding of the parallel and steep sides of this narrow island. Some
of the fissures near the cliffs were a yard wide. Many enormous masses had already fallen on
the beach; and the inhabitants thought that when the rains commenced far greater slips would
happen. The effect of the vibration on the hard primary slate, which composes the foundation of
the island, was still more curious: the superficial parts of some narrow ridges were as complete-
ly shivered as if they had been blasted by gunpowder. This effect, which was rendered conspic-
uous by the fresh fractures and displaced soil, must be confined to near the surface, for other-
wise there would not exist a block of solid rock throughout Chile; nor is this improbable, as it is
known that the surface of a vibrating body is affected differently from the central part. It is, per-
haps, owing to this same reason, that earthquakes do not cause quite such terrific havoc within
deep mines as would be expected. I believe this convulsion has been more effectual in lessening
the size of the island of Quiriquina, than the ordinary wear-and-tear of the sea and weather dur-
ing the course of a whole century….

Galapagos Islands, Ecuador

September 15, 1835 - November 15, 1835

This archipelago consists of ten principal islands, of which five exceed the
others in size. They are situated under the Equator, and between five and six hundred miles
westward of the coast of America. They are all formed of volcanic rocks; a few fragments of
granite curiously glazed and altered by the heat, can hardly be considered as an exception.
Some of the craters, surmounting the larger islands, are of immense size, and they rise to a
height of between three and four thousand feet. Their flanks are studded by innumerable small-
er orifices. I scarcely hesitate to affirm, that there must be in the whole archipelago at least two
thousand craters. These consist either of lava or scoriæ, or of finely-stratified, sandstone-like
tuff. Most of the latter are beautifully symmetrical; they owe their origin to eruptions of volcanic mud without any lava: it is a remarkable circumstance that every one of the twenty-eight
tuff-craters which were examined, had their southern sides either much lower than the other
sides, or quite broken down and removed. As all these craters apparently have been formed
when standing in the sea, and as the waves from the trade wind and the swell from the open
Pacific here unite their forces on the southern coasts of all the islands, this singular uniformity
in the broken state of the craters, composed of the soft and yielding tuff, is easily explained.
Considering that these islands are placed directly under the equator, the climate is far from
being excessively hot; this seems chiefly caused by the singularly low temperature of the sur-
rounding water, brought here by the great southern
Polar current. Excepting during one short season, very little rain falls, and even then it is irregu-
lar; but the clouds generally hang low. Hence, whilst the lower parts of the islands are very ster-
ile, the upper parts, at a height of a thousand feet and upwards, possess a damp climate and a
tolerably luxuriant vegetation. This is especially the case on the windward sides of the islands,
which first receive and condense the moisture from the atmosphere….
We doubled the south-west extremity of Albemarle Island….
The rocks on the coast abounded with great black lizards, between three and four feet long; and
on the hills, an ugly yellowish-brown species was equally common. We saw many of this latter
kind, some clumsily running out of the way, and others shuffling into their burrows. I shall
presently describe in more detail the habits of both these reptiles. The whole of this northern
part of Albemarle Island is miserably sterile….
The natural history of these islands is eminently curious, and well deserves attention. Most of
the organic productions are aboriginal creations, found nowhere else; there is even a difference
between the inhabitants of the different islands; yet all show a marked relationship with those of
America, though separated from that continent by an open space of ocean, between 500 and 600
miles in width. The archipelago is a little world within itself, or rather a satellite attached to
America, whence it has derived a few stray colonists, and has received the general character of
its indigenous productions. Considering the small size of the islands, we feel the more aston-
ished at the number of their aboriginal beings, and at their confined range. Seeing every height
crowned with its crater, and the boundaries of most of the lava-streams still distinct, we are led
to believe that within a period geologically recent the unbroken ocean was here spread out.
Hence, both in space and time, we seem to be brought somewhat near to that great fact -- that
mystery of mysteries -- the first appearance of new beings on this earth The remaining land-birds form a most singular group of finches, related to each other in the
structure of their beaks, short tails, form of body and plumage: there are thirteen species, which
Mr. Gould has divided into four sub-groups. All these species are peculiar to this archipelago; and so is the whole group, with the exception of one species of the sub-group Cactornis, lately
brought from Bow Island, in the Low Archipelago. Of Cactornis, the two species may be often
seen climbing about the flowers of the great cactus-trees; but all the other species of this group
of finches, mingled together in flocks, feed on the dry and sterile ground of the lower districts.
The males of all, or certainly of the greater number, are jet black; and the females (with perhaps
one or two exceptions) are brown. The most curious fact is the perfect gradation in the size of
the beaks in the different species of Geospiza, from one as large as that of a hawfinch to that of
a chaffinch, and (if Mr. Gould is right in including his sub-group, Certhidea, in the main group)
even to that of a warbler. The largest beak in the genus Geospiza is shown in Fig. 1, and the
smallest in Fig. 3; but instead of there being only one intermediate species, with a beak of the
size shown in Fig. 2, there are no less than six species with insensibly graduated beaks. The
beak of the sub-group Certhidea, is shown in Fig. 4. The beak of Cactornis is 1. Geospiza magnirostris. 2. Geospiza fortis. 3. Geospiza parvula. 4. Certhidea olivasea. somewhat like that of a starling, and that of the fourth sub-group, Camarhynchus, is slightly
parrot-shaped. Seeing this graduation and diversity of structure in one small, intimately related
group of birds, one might really fancy that from an original paucity of birds in this archipelago,
one species had been taken and modified for different ends.
I will first describe the habits of the large tortoises (Testudo nigra, formerly called Indica),
which has been so frequently alluded to. These animals are found, I believe, on all the islands
of the archipelago; certainly on the greater number. They frequent in preference the high damp
parts, but they likewise live in the lower and arid districts. I have already shown, from the num-
bers which have been caught in a single day, how very numerous they must be. Some grow to
an immense size: Mr. Lawson, an Englishman, and vice-governor of the colony, told us that he
had seen several so large, that it required six or eight men to lift them from the ground; and that
some had afforded as much as two hundred pounds of meat. The old males are the largest, the
females rarely growing to so great a size: the male can readily be distinguished from the female
by the greater length of its tail. The tortoises which live on those islands where there is no
water, or in the lower and arid parts of the others, feed chiefly on the succulent cactus. Those
which frequent the higher and damp regions, eat the leaves of various trees, a kind of berry
(called guayavita) which is acid and austere, and likewise a pale green filamentous lichen
(Usnera plicata), that hangs from the boughs of the trees…. I have not as yet noticed by far the most remarkable feature in the natural history of this archi-
pelago; it is, that the different islands to a considerable extent are inhabited by a different set of
beings. My attention was first called to this fact by the Vice-Governor, Mr. Lawson, declaring
that the tortoises differed from the different islands, and that he could with certainty tell from
which island any one was brought. I did not for some time pay sufficient attention to this statement, and I had already partially mingled together the collections from two of the islands. I never dreamed that islands, about 50 or 60 miles apart, and most of them in sight of each other,
formed of precisely the same rocks, placed under a quite similar climate, rising to a nearly
equal height, would have been differently tenanted; but we shall soon see that this is the case. It
is the fate of most voyagers, no sooner to discover what is most interesting in any locality, than
they are hurried from it; but I ought, perhaps, to be thankful that I obtained sufficient materials
to establish this most remarkable fact in the distribution of organic beings.