A Journey in Brazil

by Louis Agassiz; Elizabeth Cabot Cary Agassiz

January 8th.—Manaos. The necessity for some days of rest, after so many months of unintermitted work, has detained Mr. Agassiz here for a week. It has given us an opportunity of renewing our walks in the neighborhood of Manaos, of completing our collection of plants, and also of refreshing our memory of scenes which we shall probably never see again, and among which we have had a pleasant home for nearly three months. The woods are much more full of flowers than they were when I first became acquainted with their many pleasant paths. Passion-flowers are especially abundant. There is one kind which has a delicious perfume, not unlike Cape Jessamine. It hides itself away in the shade, but its fragrance betrays it; and if you put aside the branches of the trees, you are sure to find its large white-and-purple flowers, and dark, thick-leaved vine, climbing up some neighboring trunk. Another, which seems rather to court than avoid observation, is of a bright red; and its crimson stars are often seen set, as it were, in the thick foliage of the forest. But, much as I enjoy the verdure here, I appreciate, more than ever before, the marked passage of the seasons in our Northern hemisphere. In this unchanging, green world, which never alters from century to century, except by a little more or less moisture, a little more or less heat, I think with the deepest gratitude of winter and spring, summer and autumn. The circle of nature seems incomplete, and even the rigors of our climate are remembered with affection in this continual vapor-bath. It is literally true that you cannot move ten steps without being drenched in perspiration. However, this character of the heat prevents it from being scorching; and we have no reason to change our first impression, that, on the whole, the climate is much less oppressive than we expected to find it, and the nights are invariably cool.

At the end of this week we resume our voyage on board the “Ibicuhy,” going slowly down to Pará, stopping at several points on the way. Our first station will be at Villa Bella, where Mr. Agassiz wishes to make another collection of fishes. It may seem strange that, after having obtained, nearly five months ago, very large collections from the Amazons itself at this point, as well as from the lakes in the neighborhood, he should return to the same locality, instead of choosing another region for investigation. Were his object merely or mainly to become acquainted with the endless diversity of fishes he now knows to exist in this immense fresh-water basin, such a repetition of specimens from the same locality would certainly be superfluous, since it is probable that a different point would be more prolific in new species. The mere accumulation of species is, however, entirely subordinate to the object which he has kept in view ever since he began his present researches, namely, that of ascertaining by direct observation the geographical range of the fishes, and determining whether their migrations are so frequent and extensive as they are said to be. I make an extract from Mr. Agassiz’s notes on this subject.

“I have been frequently told here that the fishes were very nomadic, the same place being occupied at different seasons of the year by different species. My own investigations have led me to believe that these reports are founded on imperfect observations, and that the localization of species is more distinct and permanent in these waters than has been supposed; their migrations being, indeed, very limited, consisting chiefly in rovings from shallower to deeper waters, and from these to shoals again, at those seasons when the range of the shore in the same water-basin is affected by the rise and fall of the river;—that is to say, the fishes found at the bottom of a lake covering perhaps a square mile in extent, when the waters are lowest, will appear near the shores of the same lake when, at the season of high waters, it extends over a much wider area. In the same way, fishes which gather near the mouth of a rivulet, at the time of low waters, will be found as high as its origin at the period of high waters; while fishes which inhabit the larger igarapés on the sides of the Amazons when they are swollen by the rise of the river, may be found in the Amazons itself when the stream is low. There is not a single fish known to ascend from the sea to the higher courses of the Amazons at certain seasons, and to return regularly to the ocean. There is no fish here corresponding to the salmon, for instance, which ascends the streams of Europe and North America to deposit its spawn in the cool head-waters of the larger rivers, and then returns to the sea. The wanderings of the Amazonian fishes are rather a result of the alternate widening and contracting of their range by the rise and fall of the waters, than of a migratory habit; and may be compared to the movements of those oceanic fishes which, at certain seasons, seek the shoals near the shore, while they spend the rest of the year in deeper waters.

“Take our shad as an example. It is caught on the coast of Georgia in February, on the Carolina shores a little later; in March it may be found in Washington and Baltimore, next in Philadelphia and New York; and it does not make its appearance in the Boston market (except when brought from farther south) before the latter part of April, or the beginning of May. This sequence has led to the belief that the shad migrates from Georgia to New England. An examination of the condition of these fishes, during the months when they are sold in our markets, shows at once that this cannot be the case. They are always full of roe, and, being valued for the table at this period, they are brought to market at each locality until the spawning season is over. Now, as they cannot breed twice within a few weeks, it is evident that the shad which make their appearance successively along the Atlantic coast from February to May are not the same. It is the spring which migrates northward, calling up the shoals of shad from the deeper sea, as it touches in succession different points along the shore. Such movements, if thus connected with the advancing spring along a whole coast, appear to be migrations from south to north, when they are, in fact, only the successive rising of the same species from deeper to shallower waters at the breeding season. In the same way it is probable that the inequality in the seasons of rise and fall, between the different tributaries of the Amazons and the various parts of its own course, may give a sequence to the appearance of the fish in certain localities, which seems like migration without being so, in fact.

“Keeping in view all the information I could obtain upon this subject, I have attempted, wherever it was possible to do so, to make collections simultaneously at different points of the Amazons: thus, while I was collecting at Villa Bella six months ago, some of my assistants were engaged in the same way at Santarem, and higher up on the Tapajoz; while I was working at Teffé, parties were busy in the Hyavary, the Iça, and the Hyutahy; and during my last stay at Manaos, parties have been collecting at Cudajas and at Manacaparu, and higher up on the Rio Negro, as well as at some lower points on the main river. At some of these stations I have been able to repeat my investigations at different seasons, though the intervals between the earlier and later collections made at the same localities have, of course, not been the same. Between the first collections made at Teffé and the last, hardly two months intervened, while those made on our first arrival at Manaos in September up to the present time cover an interval of four months; from the first to the last at Villa Bella more than five months will have elapsed. On this account I attach great importance to the renewal of my investigations at that place, as well as to the later collections from Obydos, Santarem, Monte Alegre, Porto do Moz, Gurupá, Tajapurú, and Pará. As far as these comparisons have gone, they show that the distinct faunæ of the above-named localities are not the result of migrations; for not only have different fishes been found in all these basins at the same time, but at different times the same fishes have been found to recur in the same basins, whenever the fishing was carried on, not merely in favored localities, but as far as possible over the whole area indiscriminately, in deep and shoal waters. Should it prove that at Pará, as well as at the intervening stations, after an interval of six months, the fishes are throughout the same as when we ascended the river, the evidence against the supposed extensive migrations of the Amazonian fishes will certainly be very strong. The striking limitation of species within definite areas does not, however, exclude the presence of certain kinds of fish simultaneously throughout the whole Amazonian basin. The Pirarucu, for instance, is found everywhere from Peru to Pará; and so are a few other species more or less extensively distributed over what may be considered distinct ichthyological faunæ. But these wide-spread species are not migratory; they have normally and permanently a wide range, just as some terrestrial animals have an almost cosmopolite character, while others are circumscribed within comparatively narrow limits. Though most quadrupeds of the United States, for instance, differ from those of Mexico and Brazil, constituting several distinct faunæ, there is one, the puma or red lion, the panther of the North, which is found on the east of the Rocky Mountains and the Andes, from Patagonia to Canada.

“The movement of the waters, which affects so powerfully the distribution of the fishes, forms in itself a very curious phenomenon. There is, as it were, a rhythmical correspondence in the rise and fall of the affluents on either shore of the Amazons, causing the great body of the water, in its semiannual tides, to sway alternately more to the north or to the south. On the southern side of the valley, the rains begin in the months of September and October. They pour down from the table-lands of Brazil and the mountains of Bolivia with cumulative force, gathering strength as the rainy season progresses, swelling the head-waters of the Purus, Madeira, Tapajoz, and other southern tributaries, and gradually descending to the main stream. The process is a slow one, however, and the full force of the new flood is not felt in the Amazons until February and March. During the month of March, in the region below the confluence of the Madeira, for instance, the rise of the Amazons averages a foot in twenty-four hours, so great is the quantity of water poured into it. At about the same period with the southern rains, or a little earlier, say in the months of August and September, the snows in the Andes begin to melt and flow down towards the plain. This contribution from the Cordilleras of Peru and Equador, coinciding with that from the highlands of Brazil and Bolivia, swells the Amazons in its centre and on its southern side to such an extent that the bulk of the water pushes northward, crowding upon its northern shore, and flowing even into the tributaries which open on that side of the river, and are now at their lowest ebb. Presently, however, the rains on the table-lands of Guiana, and on the northern spurs of the Andes, where the rainy season prevails chiefly in February and March, repeat the same process in their turn. During April and May the northern tributaries are rising, and they reach their maximum in June. Thus, at the end of June, when the southern rivers have already fallen considerably, the northern rivers are at their flood-tide. The Rio Negro, for instance, rises at Manaos to about forty-five feet above its lowest level. This mass of water from the north now presses against that in the centre, and bears it southward again. The rainy season along the course of the Amazons is from December till March, corresponding very nearly, in the time of the year and in duration, with our winter. It must be remembered that the valley of the Amazons is not a valley in the ordinary sense, bordered by walls or banks enclosing the waters which flow between. It is, on the contrary, a plain some seven or eight hundred miles wide and between two and three thousand miles long, with a slope so slight that it hardly averages more than a foot in ten miles. Between Obydos and the sea-shore, a distance of about eight hundred miles, the fall is only forty-five feet; between Tabatinga and the sea-shore, a distance of more than two thousand miles in a straight line, the fall is about two hundred feet. The impression to the eye is, therefore, that of an absolute plain; and the flow of the water is so gentle that, in many parts of the river, it is hardly perceptible. Nevertheless, it has a steady movement eastward, descending the gentle slope of this wide plain, from the Andes to the sea; this movement, aided by the interflow from the south and north at opposite seasons, presses the bulk of the water to its northernmost reach during our winter months, and to its southernmost limit during our summer months. In consequence of this, the bottom of the valley is constantly shifting, and there is a tendency to form channels from the main river to its tributaries, such as we have seen to exist between the Solimoens and the Rio Negro,—such as Humboldt mentions between the Hyapura and the Amazons. Indeed, all these rivers are bound together by an extraordinary network of channels, forming a succession of natural highways which will always make artificial roads, to a great degree, unnecessary. Whenever the country is settled, it will be possible to pass from the Purus, for instance, to the Madeira, from the Madeira to the Tapajoz, from the Tapajoz to the Xingu, and thence to the Tocantins, without entering the course of the main river. The Indians call these passes ‘furo,’ literally, a bore,—a passage pierced from one river to another. Hereafter, when the interests of commerce claim this fertile, overflowed region, these channels will be of immense advantage for intercommunication.”

CHAPTER XII.
DESCENDING THE RIVER TO PARÁ.—EXCURSIONS ON THE COAST.

Farewell Visit to the Great Cascade at Manaos.—Change in its Aspect.—Arrival at Villa Bella.—Return to the House of the Fisherman Maia.—Excursion to the Lago Maximo.—Quantity of Game And Waterfowl.—Victoria Regia.—Leave Villa Bella.—Arrive at Obydos.—Its Situation and Geology.—Santarem.—Visit to the Church.—Anecdote of Martius.—A Row overland.—Monte Alégre.—Picturesque Scenery.—“Banheiras.”—Excursion into the Country.—Leave Monte Alégre.—Anecdote of Indians.—Almeyrim.—New Geological Facts.—Porto do Moz.—Collections.—Gurupá.—Tajapurú.—Arrive at Pará.—Religious Procession.—Excursion To Marajo.—Sourés.—Jesuit Missions.—Geology of Marajo.—Buried Forest.—Vigia.—Igarapé.—Vegetation and Animal Life.—Geology.—Return to Pará.—Photographing Plants.—Extract from Mr. Agassiz’s Notes on the Vegetation of the Amazons.—Prevalence Of Leprosy.

January 15th.—To-day finds us on our way down the Amazons in the “Ibicuhy.” The day before leaving Manaos we paid a last visit to the great cascade, bathed once more in its cool, delicious waters, and breakfasted by the side of the fall. Before many weeks are over, the cascade will have disappeared; it will be drowned out, as it were, for the igarapé is filling rapidly with the rise of the river, and will soon reach the level of the sandstone shelf over which the water is precipitated. Already the appearance of the spot is greatly changed since we were there before. The banks are overflowed; the rocks and logs which stood out from the water are wholly covered; and where there was only a brawling stream, so shallow that it hardly afforded depth for the smallest canoe, there is now a not insignificant river. Indeed, everywhere we see signs of the changes wrought by the “enchente.” The very texture of the Amazons is changed; it is thicker and yellower than when we ascended it, and much more laden with floating wood, detached grasses, and débris of all sorts washed from the shore. Wild-flowers are also more abundant than they were when we came up the river in September; not delicate, small plants, growing low among moss and grass, as do our violets, anemones, and the like; but large blossoms, covering tall trees, and resembling exotics at home, by their rich color and powerful odor. Indeed, the flowers of the Amazonian forests always remind me of hot-house plants: and there often comes a warm breath from the depths of the woods, laden with moisture and perfume, like the air from the open door of a conservatory.

January 17th.—We reached Villa Bella at eight o’clock yesterday morning, but waited there only a few hours to make certain necessary arrangements, and then kept on to the mouth of the river Ramos, an hour’s sail from the town,—the same river which we had ascended from its upper point of juncture with the Amazons, on our excursion to Mauhes. We anchored at a short distance from the entrance, before the house of our old acquaintances, the Maias, where, it may be remembered, we passed a few days when collecting in this neighborhood before. Fortunately, Maia himself was in Manaos when we left, employed as a soldier in the National Guard; and the President kindly gave him leave to accompany us, that Mr. Agassiz might have the advantage of his familiarity with the locality, and his experience in fishing. The man himself was pleased to have an opportunity of visiting his family, to whom his coming was an agreeable surprise. We went on shore this morning to make them a visit, taking with us some little souvenirs, such as beads, trinkets, knives, &c. We were received as old friends, and made welcome to all the house would afford; but, though as clean as ever, it looked poorer than on our former visit. I saw neither dried fish nor mandioca nor farinha, and the woman told me that she found it very hard to support her large family, now that the husband and father was away.