Narrative of the surveying voyages of His Majesty's Ships Adventure and Beagle, Vol. 3 [of 3] · Charles Darwin
BUENOS AYRES TO ST. FE.
SEPTEMBER 27TH.--In the evening I set out on an excursion to St. Fe, which is situated nearly three hundred English miles from Buenos Ayres, on the banks of the Parana. The roads in the neighbourhood of the city, after the rainy weather were extraordinarily bad. I should never have thought it possible for a bullock-waggon to have crawled along: as it was, they scarcely went at the rate of a mile an hour, and a man was kept ahead, to survey the best line for making the attempt. The bullocks were terribly jaded: it is a great mistake to suppose that with improved roads, and an accelerated velocity of travelling, the sufferings of the animals increase in the same proportion. We passed a train of waggons and a troop of beasts on their road to Mendoza. The distance is about 580 geographical miles, and the journey is generally performed in fifty days. These waggons are very long, narrow, and thatched with reeds; they have only two wheels, the diameter of which in some cases is even ten feet. Each is drawn by six bullocks which are urged on by a goad at least twenty feet long: this is suspended from within the roof; for the wheel bullocks a smaller one is kept; and for the intermediate pair, a point projects at right angles from the middle of the long one. The whole apparatus looked like some implement of war.
SEPTEMBER 28TH.--We passed the small town of Luxan, where there is a wooden bridge over the river--a most unusual convenience in this country. We passed also Areco. The plains appeared level, but were not so in fact; for in various places the horizon was distant. The estancias are here wide apart; for there is little good pasture, owing to the land being covered by beds either of an acrid clover, or of the great thistle. The latter, well known from the animated description given by Sir F. Head, were at this time of the year two-thirds grown; in some parts they were as high as the horse’s back, but in others they had not yet sprung up, and the ground was bare and dusty as on a turnpike road. The clumps were of the most brilliant green, and they made a pleasing miniature-likeness of broken forest land. When the thistles are fully grown, the great beds are impenetrable, except by a few tracks, as intricate as those in a labyrinth. These are only known to the robbers, who at this season inhabit them, and sally forth at night to rob, and cut throats, with impunity. Upon asking at a house whether robbers were numerous, I was answered, “The thistles are not up yet;”--the meaning of which reply was not at first very obvious. There is little interest in passing over these tracts, for they are inhabited by few animals or birds, excepting the bizcacha and its friend the little owl.
The bizcacha[1] is well known to form a prominent feature in the zoology of the Pampas. It is found as far south as the Rio Negro, in lat. 41°, but not beyond. It cannot, like the agouti, subsist on the gravelly and desert plains of Patagonia, but prefers a clayey or sandy soil, which produces a different and more abundant vegetation. Near Mendoza, at the foot of the Cordillera, it occurs in close neighbourhood with the allied alpine species. It is a very curious circumstance in its geographical distribution, that it has never been seen, fortunately for the inhabitants, in Banda Oriental, to the eastward of the river Uruguay: yet in that province there are plains which appear admirably adapted to its habits. That river has formed an insuperable obstacle to its migration; although the broader barrier of the Parana has been passed, and the bizcacha is common in Entre Rios (the province between the two rivers), directly on the opposite shore of the Uruguay. Near Buenos Ayres these animals are exceedingly common. Their most favourite resort appears to be those parts of the plain, which during one half the year are covered with giant thistles, to the exclusion of other plants. The Gauchos affirm that it lives on roots; which, from the great strength of its gnawing teeth, and the kind of localities frequented by it, seems probable. As in the case of the rabbit, a few holes are commonly placed together. In the evening the bizcachas come out in numbers, and there quietly sit on their haunches. They are at such times very tame, and a man on horseback passing by, seems only to present an object for their grave contemplation. They do not wander far from their burrows. They run very awkwardly, and, when hurrying out of danger, from their elevated tails and short front legs much resemble great rats. Their flesh, when cooked, is very white and good, but it is seldom used.
The bizcacha has one very singular habit; namely, dragging every hard object to the mouth of its burrow. Around each group of holes many bones of cattle, stones, thistle-stalks, hard lumps of earth, dry dung, &c., are collected into a scattered heap, which frequently amounts to as much as a wheel-barrow would contain. I was credibly informed that a gentleman, when riding on a dark night, dropped his watch; he returned in the morning, and by searching the neighbourhood of every bizcacha hole on the line of road, as he expected, soon found it. This habit of picking up whatever may be lying on the ground any where near its habitation, must cost much trouble. For what purpose it is done I am quite unable to form even the most remote conjecture: it cannot be for defence, because the rubbish is chiefly placed above the mouth of the burrow, which enters the ground at a very small inclination. No doubt there must exist some good reason; but the inhabitants of the country are quite ignorant respecting it.
The little owl (_Noctua cunicularia_), which has been so often mentioned, on the plains of Buenos Ayres exclusively inhabits the holes of the bizcacha; but in Banda Oriental it is its own workman. During the open day, but more especially in the evening, these birds may be seen in every direction standing frequently by pairs on the hillock near their burrows. If disturbed they either enter the hole, or, uttering a shrill harsh cry, move with a remarkably undulatory flight to a short distance, and then turning round, steadily gaze at their pursuer. Occasionally in the evening they may be heard hooting. I found in the stomachs of two which I opened the remains of mice, and I one day saw a small snake killed and carried away. It is said these latter animals are their common prey during the daytime. I may here mention, as showing on what various kinds of food owls subsist, that a species that was killed among the islets of the Chonos Archipelago, had its stomach full of good-sized crabs. In the evening we crossed the Rio Arrecife, on a simple raft made of barrels lashed together, and slept at the post-house on the other side. I this day paid horse hire for thirty-one leagues; and although the sun was glaring hot I was but very little fatigued. When Captain Head talks of riding fifty leagues a day, I do not imagine the distance is equal to 150 English miles. At all events the thirty-one leagues was only 76 miles in a straight line, and in an open country I should think four additional miles for turnings would be a sufficient allowance.
29TH AND 30TH.--We continued to ride over plains of the same character. At San Nicholas I first saw the noble river of the Parana. At the foot of the cliff on which the town stands, some large vessels were at anchor. Before arriving at Rozario, we crossed the Saladillo, a stream of fine clear running water, but too saline to drink. Rozario is a large town built on a dead level plain, which forms a cliff about sixty feet high over the Parana. The river here is very broad, with many islands, which are low and wooded, as is also the coast of the opposite shore. The view would resemble that of a great lake, if it were not for the linear-shaped islets, which alone give the idea of running water. The cliffs are the most picturesque part; sometimes they are absolutely perpendicular, and of a red colour; at other times in large broken masses, covered with cacti and mimosa-trees. The real grandeur, however, of an immense river like this, is derived from reflecting how important a means of communication and commerce, it forms between one nation and another; to what a distance it travels; and from how vast a territory it drains the great body of fresh water which flows past your feet.
For many leagues north and south of San Nicholas and Rozario, the country is really level. Scarcely any thing which travellers have written about its extreme flatness, can be considered as exaggeration. Yet I could never find a spot, where, by slowly turning round, objects were not seen at greater distances in some directions than in others; and this manifestly proves inequality in the plain. At sea, a person’s eye being six feet above the surface of the water, his horizon is two miles and four-fifths distant. In like manner, the more level the plain, the more nearly does the horizon approach within these narrow limits: and this, in my opinion, entirely destroys that grandeur, which one would have imagined that a vast level plain would have possessed. OCTOBER 1ST.--We started by moonlight and arrived at the Rio Tercero by sunrise. This river is also called the Saladillo, and it deserves the name, for the water is brackish.
I staid here the greater part of the day, searching for fossil bones. Falconer mentions having seen, in the bed of this river, great bones, and the case of a giant armadillo. By good fortune, I discovered a tooth embedded in a layer of rock marl, which was afterwards found exactly to fit the socket in the head of a strange animal, the Toxodon, which will presently be mentioned. Hearing also of the remains of one of the old giants, which a man told me he had seen on the banks of the Parana, I procured a canoe, and proceeded to the place. Two groups of immense bones projected in bold relief from the perpendicular cliff. They were, however, so completely decayed, that I could only bring away small fragments of one of the great molar-teeth; but these were sufficient to show that the remains belonged to a species of Mastodon. The men who took me in the canoe, said they had long known of them, and had often wondered how they had got there: the necessity of a theory being felt, they came to the conclusion, that, like the bizcacha, the mastodon formerly was a burrowing animal! In the evening we rode another stage, and crossed the Monge, another brackish stream, bearing the dregs of the washings of the Pampas.
OCTOBER 2D.--We passed through Corunda, which, from the luxuriance of its gardens, was one of the prettiest villages I saw. From this point to St. Fe the road is not very safe. The western side of the Parana further northward, ceases to be inhabited; and hence the Indians sometimes come down, and waylay travellers. The nature of the country also favours this, for instead of a grassy plain, there is an open woodland, composed of low prickly mimosas. We passed some houses that had been ransacked and since deserted; we saw also a spectacle, which my guides viewed with high satisfaction; it was the skeleton of an Indian with the dried skin hanging on the bones, suspended to the branch of a tree. In the morning we arrived at St. Fe. I was surprised to observe how great a change of climate a difference of only three degrees of latitude between this place and Buenos Ayres had caused. This was evident from the dress and complexion of the men--from the increased size of the ombu-trees--the number of new cacti and other plants--and especially from the birds. In the course of an hour I remarked half-a-dozen of the latter, which I had never seen at Buenos Ayres. Considering that there is no natural boundary between the two places, and that the character of the country is nearly similar, the difference was much greater than I should have expected.
OCTOBER 3D AND 4TH.--I was confined to my bed by a headach for these two days. A goodnatured old woman, who attended me, wished me to try many odd remedies. A common practice is, to bind an orange-leaf, or a bit of black plaster, to each temple; and a still more general plan is, to split a bean into halves, moisten them, and place one on each temple, where they will easily adhere. It is not thought proper ever to remove the beans or plaster, but to allow them to drop off; and sometimes, if a man, with patches on his head, is asked, what is the matter? he will answer, “I had a headache the day before yesterday.” St. Fe is a quiet little town, and is kept clean, and in good order. The governor, Lopez, was a common soldier at the time of the revolution; but has now been seventeen years in power. This stability of government is owing to his tyrannical habits; for tyranny seems as yet better adapted to these countries, than republicanism. The governors favourite occupation is hunting Indians: a short time since he slaughtered forty-eight, and sold the children at the rate of three or four pounds apiece.
OCTOBER 5TH.--We crossed the Parana to St. Fe Bajada, a town on the opposite shore. The passage took some hours, as the river here consisted of a labyrinth of small streams, separated by low wooded islands. I had a letter of introduction to an old Catalonian Spaniard, who treated me with the most uncommon hospitality. The Bajada is the capital of Entre Rios. In 1825 the town contained 6000 inhabitants, and the province 30,000; yet, few as they are, none have suffered more from bloody and desperate revolutions. They boast here of representatives, ministers, a standing army, and governors: so it is no wonder that they have their revolutions. At some future day this must be one of the richest countries of La Plata. The soil is varied and productive, and its almost insular form gives it two grand lines of communication by the rivers Parana and Uruguay. I was delayed here five days, and employed myself in examining the geology of the surrounding country, which was very interesting. We here see beds of sand, clay, and limestone, containing sea-shells and sharks’ teeth, passing above into an indurated marl, and from that into the red clayey earth of the Pampas, with its calcareous concretions and the bones of terrestrial animals. This vertical section clearly tells us, of a large bay of pure salt-water, gradually encroached on, and at last becoming the bed of a muddy estuary, into which floating carcasses were swept. I found near the Bajada a large piece, nearly four feet across, of the giant armadillo-like case; also a molar tooth of a mastodon, and fragments of very many bones, the greater number of which were rotten, and as soft as clay.
A tooth which I discovered by one point projecting from the side of a bank, interested me much, for I at once perceived that it had belonged to a horse. Feeling much surprise at this, I carefully examined its geological position, and was compelled to come to the conclusion,[2] that a horse, which cannot from a comparison of the tooth alone, be distinguished from the existing species,[3] lived as a contemporary with the various great monsters that formerly inhabited South America. Mr. Owen and myself, at the College of Surgeons, compared this tooth with a fragment of another, probably belonging to the Toxodon, which was embedded at the distance only of a few yards in the same earthy mass. No sensible difference in their state of decay could be perceived; they were both tender, and partially stained red. If the horse did not coexist with the Toxodon, the tooth must by some accident, not very easily understood, have been embedded within the last three centuries (the period of the introduction of the horse), with the remains of those animals, which ages since perished, when the Pampas was covered by the waters of the sea. Now, I may ask, will any one credit that two teeth of nearly equal size, buried in the same substance close together, after a period of so vast an inequality, could exist in the same condition of decay? We must conclude otherwise. Certainly it is a marvellous event in the history of animals, that a native kind should have disappeared[4] to be succeeded in after ages by the countless herds introduced with the Spanish colonist! But our surprise should be modified when it is already known, that the remains of the _Mastodon angustidens_ (the tooth formerly alluded to as embedded near that of the horse, probably belonged to this species) have been found both in South America, and in the southern parts of Europe.
With regard to North America, Cuvier says[5] the _Elephas primigenius_ “has left thousands of its carcasses from Spain to the shores of Siberia, and it has been found in the whole of North America.” The fossil ox, in a like manner, he writes,[6] is buried “dans toute la partie boréale des deux continens, puisque on en a d’Allemagne, d’Italie, de Prussie, de la Sibérie occidentale et orientale, et de l’Amérique.” I may here add that horses’ bones, mingled with those of the mastodon, have several times been transmitted for sale from North America to England, but it has always been imagined, from the simple fact of their being horses’ bones, that they had been accidentally mingled with the fossils. Among the remains brought home by Captain Beechey from the west coast of the same continent, in the frozen region of 66° north, Dr. Buckland[7] has described the astragalus metacarpus, and metatarsus of the horse, which were associated with the remains of the _Elephas primigenius_, and of the fossil ox. Thus we have an elephant, an ox, and a horse (the species of the latter is only presumed to be identical), common to Europe and to North America.
Very few species of living quadrupeds,[8] which are altogether terrestrial in their habits, are common to the two continents, and these few are chiefly confined to the extreme frozen regions of the north. The separation, therefore, of the Asiatic and American zoological provinces appears formerly to have been less perfect than at present. The remains of the elephant and of the ox have been found on the banks of the Anadir (long. 175° E.), on the extreme part of Siberia, nearest the American coast: and the former remains, according to Chamisso, are common in the peninsula of Kamtschatka. On the opposite shores, likewise, of the narrow strait which divides these two great continents, we know, from the discoveries of Kotzebue and Beechey, that the remains of both animals occur abundantly: and as Dr. Buckland has shown they are associated with the bones of the horse, the teeth of which animal in Europe, according to Cuvier, accompany by thousands the remains of the pachydermata of the later periods. With these facts, we may safely look at this quarter, as the line of communication (now interrupted by the steady progress of geological change) by which the elephant, the ox, and the horse, entered America, and peopled its wide extent.[9]
The occurrence of the fossil horse and of _Mastodon angustidens_ in South America, is a much more remarkable circumstance than that of the animals mentioned above in the northern half of the continent; for if we divide America, not by the Isthmus of Panama, but by the southern part of Mexico,[10] in lat. 20°, where the great table-land presents an obstacle to the migration of species, by affecting the climate, and by forming, with the exception of some valleys and of a fringe of low land on the coast, a broad barrier; we shall then have two zoological provinces strongly contrasted with each other. Some few species alone have passed the barrier, and may be considered as wanderers, such as the puma, opossum, kinkajou, and peccari. The mammalogy of South America is characterized by possessing several species of the genera of llama, cavy (and the allied animals), tapir, peccari, opossum, anteater, sloth, and armadillo. If North America had possessed species of these genera proper to it, the distinction of the two provinces could not have been drawn; but the presence of a few wanderers scarcely affects the case. North America, on the other hand, is characterized by its numerous rodents,[11] and by four genera of solid horned ruminants,[12] of which section the southern half does not possess a single species.
This distinction of the two zoological provinces does not appear always to have existed. At the present day the order of Edentata is much more strongly developed in South America, than in any other part of the world: and concluding from the fossil remains, which were discovered at Bahia Blanca, such must have been the case during a former epoch. In America, north of Mexico, not one of this order is now found: yet, as is well known, the gigantic megalonyx, considered by Cuvier as a species of Megatherium, has been found only in that country; and as it appears from recent observations,[13] the Megatherium Cuvierii itself likewise occurs there. Mr. Owen showed me the tibia of some large animal, which Sir Philip Egerton had purchased out of a collection of the remains of the mastodon brought from North America. Mr. Owen says it certainly belongs to one of the Edentata, and it so closely resembles a bone which I found embedded, together with fragments of the great armadillo-like covering, in Banda Oriental, that it probably forms a species of the same genus. Lastly, among the fossils brought home by Captain Beechey from the N.W. coast, there was a cervical vertebra, which, when compared by Mr. Pentland[14] with the skeletons at Paris, was found to resemble that of the sloth and anteater more than that of any other animal, although having some points of essential difference.
Of the Pachydermata four or five species are now found in America; but, as in the case of the Edentata, none are peculiar to the continent north of Mexico; and one alone seems to exist there as a wanderer. Yet the account of the multitude of bones of the mastodon and elephant, which have been discovered in the salt-licks of North America, is familiar to every one. The remains of the _Mastodon giganteum_ have been found nowhere else; but those of the _Elephas primigenius_ are common to a large part of the terrestrial globe.[15] This elephant must have existed in Mexico; and Cuvier,[16] judging from a fragment of a tusk, thinks it even extended to the neighbourhood of Quito in South America. In the latter country three species of Mastodon have been discovered. One of these, _M. angustidans_, is common to Europe. It is singular that its remains, as yet, have never been brought from North America; nevertheless, considering that it was a contemporary of the extinct animals above mentioned, it seems highly probable that it arrived by the same line of communication on the N.W. coast. As its remains have frequently been found at a great elevation in the Cordillera, perhaps its habits led it to follow that chain of mountains from north to south.
After these facts, it is only in conformity with what we might almost have expected, that the horse, belonging to the same order of Pachydermata, should formerly have inhabited both North and South America. It is interesting thus to discover an epoch anterior to the division, as far at least as two important orders among the mammalia are concerned, of the continent into two separate zoological provinces. The geologist who believes in considerable oscillations of level in the crust of the globe within recent periods, will not fear to speculate either on the elevation of the Mexican platform, as a cause of the distinction, or on the submergence of land in the West Indian seas,--a circumstance which is perhaps indicated by the zoology of those islands.[17] The number of bones embedded in the grand estuary deposit of the Pampas must be very great; I myself heard of, and saw many groups. The names of such places as “the stream of the animal,” “the hill of the giant,” tell the same story. At other times I heard of the marvellous property of certain rivers, which had the power of changing small bones into large; or as some maintained, the bones themselves grew. As far as I am aware, not one of these animals, as was formerly supposed, perished in the marshes, or muddy river-beds of the present land, but their bones have been exposed by the streams intersecting the deposit in which their remains were formerly buried. We may therefore conclude that the whole area of the Pampas is one wide sepulchre for these extinct quadrupeds.
Text from Project Gutenberg, public domain in the United States.