Chapter VII: Life in Teffé (2)

_October 23d._—We left Teffé on Saturday evening on board the Icamiaba, which now seems quite like a home to us; we have passed so many pleasant hours in her comfortable quarters since we left Pará. We are just on the verge of the rainy season here, and almost every evening during the past week has brought a thunder-storm. The evening before leaving Teffé we had one of the most beautiful storms we have seen on the Amazons. It came sweeping up from the east; these squalls always come from the east, and therefore the Indians say “the path of the sun is the path of the storm.” The upper, lighter layer of cloud, travelling faster than the dark, lurid mass below, hung over it with its white, fleecy edge, like an avalanche of snow just about to fall. We were all sitting at the doorstep watching its swift approach, and Mr. Agassiz said that this tropical storm was the most accurate representation of an avalanche on the upper Alps he had ever seen. It seems sometimes as if Nature played upon herself, reproducing the same appearances under the most dissimilar circumstances. It is curious to mark the change in the river. When we reached Teffé it was rapidly falling at the rate of about a foot a day. It was easy to measure its retreat by the effect of the occasional rains on the beach. The shower of one day, for instance, would gully the sand to the water’s edge, and the next day we would find the water about a foot below the terminus of all the cracks and ruts thus caused, their abrupt close showing the line at which they met the water the previous day. Ten days or a fortnight before we left, and during which we had heavy rains at the close of every day, continuing frequently through the night, those oscillations in the river began, which the people here call “repiquete,” and which, on the Upper Amazons, precede the regular rise of the water during the winter. The first repiquete occurs in Teffé toward the end of October, accompanied by almost daily rains. After a week or so the water falls again; in ten or twelve days it begins once more to ascend, and sinks again after the same period. In some seasons there is a third rise and fall, but usually the third repiquete begins the permanent annual rise of the river. On board the steamer we were joined by Mr. Bourget, with his fine collections from Tabatinga. He, like both the other parties, has been hindered, by want of alcohol, from making as large collections as he might otherwise have done; but they are, nevertheless, very valuable, exceedingly well put up, and embracing a great variety of species, from the Marañon as well as from the Hyavary. Thus we have a rich harvest from all the principal tributaries of the Upper Amazons, within the borders of Brazil, above the Rio Negro, except the Purus, which must be left unexplored for want of time and a sufficient working force.

On leaving Teffé I should say something of the nature of the soil in connection with Mr. Agassiz’s previous observations on this subject. Although he has been almost constantly occupied with his collections, he has, nevertheless, found time to examine the geological formations of the neighborhood. The more he considers the Amazons and its tributaries, the more does he feel convinced that the whole mass of the reddish, homogeneous clay, which he has called drift, is the glacial deposit brought down from the Andes and worked over by the melting of the ice which transported it. According to his view, the whole valley was originally filled with this deposit, and the Amazons itself, as well as the rivers connected with it, are so many channels worn through the mass, having cut their way just as the igarapé now wears its way through the more modern deposits of mud and sand. It may seem strange that any one should compare the formation of these insignificant forest-streams with that of the vast river which pours itself across a whole continent; but it is, after all, only a reversal of the microscopic process of investigation. We magnify the microscopically small in order to see it, and we must diminish that which transcends our apprehension by its great size, in order to understand it. The naturalist who wishes to compare an elephant with a Coni (Hyrax),[76] turns the diminishing end of his glass upon the former, and, reducing its clumsy proportions, he finds that the difference is one of size rather than structure. The essential features are the same. So the little igarapé, as it wears its channel through the forest to-day, explains the early history of the great river and feebly reiterates the past.

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Footnote 68:

It is a curious fact, that though a large number of cows were owned in
Teffé, and were constantly seen feeding about the houses, milk was
among the unattainable luxuries. Indeed, milk is little used in
Brazil, so far as our observation goes. It is thought unhealthy for
children, and people will rather give coffee or tea to a two-year-old
baby than pure milk. The cows are never milked regularly, but the
quantity needed for the moment is drawn at any time.

Footnote 69:

TEFFÉ, September 22, 1865.

MY DEAR FRIEND AND HONORED COLLEAGUE:—Here I have been for two months
in the basin of the Amazons, and it is here that I have heard with
sorrow of the death of my old friend Valenciennes. I am the more
affected by it, because no one would have appreciated more than he the
results of my journey, which I had hoped soon to share with him. You
will naturally understand that it is to the class of fishes I
consecrate the better part of my time, and my harvest exceeds all my
anticipations. You will judge of it by a few statements.

On reaching Manaos, at the junction of the Rio Negro and the Amazons,
I had already collected more than three hundred species of fishes,
half of which have been painted from life, that is, from the fish
swimming in a large glass tank before my artist. I am often pained to
see how carelessly colored plates of these animals have been
published. Not only have we tripled the number of species, but I count
new genera by dozens, and I have five or six new families for the
Amazons, and one allied to the Gobioides entirely new to Ichthyology.
Among the small species especially I have found novelties. I have
Characines of five or six centimetres and less, adorned with the most
beautiful tints, Cyprinodonts resembling a little those of Cuba and
the United States, Scomberesoces allied to the Belone of the
Mediterranean, a considerable number of Carapoides, and Rays of
different genera from those of the ocean, and therefore not species
which ascend the river; and a crowd of Goniodonts and Chromides of
unpublished genera and species. But what I appreciate most highly is
the facility I have for studying the changes which all these fishes
undergo with age and the differences of sex among them; which are
often very considerable. Thus I have observed a species of Geophagus
in which the male has a very conspicuous protuberance on the forehead,
wholly wanting in the female and the young. This same fish has a most
extraordinary mode of reproduction. The eggs pass, I know not how,
into the mouth, the bottom of which is lined by them, between the
inner appendages of the branchial arches, and especially into a pouch,
formed by the upper pharyngials, which they completely fill. There
they are hatched, and the little ones, freed from the egg-case, are
developed until they are in a condition to provide for their own
existence. I do not yet know how long this continues; but I have
already met with specimens whose young had no longer any vitelline
sac, but were still harbored by the progenitor. As I shall still pass
a month at Teffé I hope to be able to complete this observation. The
examination of the structure of a great number of Chromides has led me
to perceive the affinities between these fishes and several other
families with which we have never thought of associating them. In the
first place, I have convinced myself that the Chromides, formerly
scattered among the Labroides and the Sciænoids, really constitute a
natural group recognized nearly at the same time and in an independent
manner by Heckel and J. Müller. But, beside these, there are the
genera Enoplosus, Pomotis, Centrarchus, and some other neighboring
genera, classed among the Percoids by all Ichthyologists, which seem
to me, from this distance and without means of direct comparison, so
near the Chromides that I do not see how they can be separated,
especially now that I know the lower pharyngials not to be invariably
soldered in the Chromides. And then the embryology and metamorphoses
of the Chromides, which I have just been studying, have convinced me
that the fishes with labyrinthic branchiæ, separated from all other
fishes by Cuvier, as a family entirely isolated on account of the
strange structure of its respiratory organs, are closely related to
the Chromides. Thus this group becomes, by its various affinities, one
of the most interesting of the class of fishes, and the basin of the
Amazons seems to be the true home of this family. I will not fatigue
you with my ichthyological researches; let me only add, that the
fishes are not uniformly spread over this great basin. I have already
acquired the certainty that we must distinguish several ichthyological
faunæ very clearly characterized. Thus the species inhabiting the
river of Pará, from the borders of the sea to the mouth of the
Tocantins, differ from those which are met in the network of
anastomoses uniting the river of Pará with the Amazons proper. The
species of the Amazons below the Xingu differ from those which occur
higher up; those of the lower course of the Xingu differ from those of
the lower course of the Tapajoz. Those of the numerous igarapés and
lakes of Manaos differ as much from those of the principal course of
the great river and of its great affluents. It remains now to study
the changes which may take place in this distribution in the course of
the year, according to the height of the waters, and perhaps also
according to the epoch at which the different species lay their eggs.
Thus far I have met but a small number of species having a very
extensive area of distribution. One of those is the Sudis gigas, found
almost everywhere. It is the most important fish of the river, that
which, as food, corresponds to cattle for the population along the
banks. Another problem to be solved is, how far this phenomenon of the
local distribution of fishes is repeated in the great affluents of the
Amazons. I shall try to solve it in ascending the Rio Negro and Rio
Madeira, and as I return to Manaos I shall be able to compare my first
observations in this locality with those of another season of the
year. Adieu, my dear friend. Remember me to M. Elie de Beaumont and to
those of my colleagues of the Academy who are interested in my present
studies. My kind remembrance also to your son.

Always yours,

L. AGASSIZ.

Footnote 70:

We found that this information was incorrect, at least for some
species, as will be seen hereafter. I let the statement stand in the
text, however, as an instance of the difficulty one has in getting
correct facts, and the danger of trusting to the observations even of
people who mean to tell the real truth. No doubt some of these Acaras
do occasionally deposit their young in the sand, and continue a
certain care of them till they are able to shift for themselves. But
the story of the fisherman was one of those half truths as likely to
mislead, as if it had been wholly false. I will add here a few details
concerning these Acaras, a name applied by the natives to all the
oval-shaped Chromides. The species which lay their eggs in the sand
belong to the genera Hydrogonus and Chætobranchus. Like the North
American Pomotis, they build a kind of flat nest in the sand or mud,
in which they deposit their eggs, hovering over them until the young
are hatched. The species which carry their young in the mouth belong
to several genera, formerly all included under the name of Geophagus
by Heckel. I could not ascertain how the eggs are brought into the
mouth, but the change must take place soon after they are laid, for I
have found in that position eggs in which the embryo had just begun
its development as well as those in a more advanced stage of growth.
Occasionally, instead of eggs, I have found the cavity of the gills,
as also the space enclosed by the branchiostegal membrane, filled with
a brood of young already hatched. The eggs before hatching are always
found in the same part of the mouth, namely, in the upper part of the
branchial arches, protected or held together by a special lobe or
valve formed of the upper pharyngeals. The cavity thus occupied by the
eggs corresponds exactly to the labyrinth of that curious family of
fishes inhabiting the East Indian Ocean, called Labyrinthici by
Cuvier. This circumstance induces me to believe that the branchial
labyrinth of the eastern fishes may be a breeding pouch, like that of
our Chromides, and not simply a respiratory apparatus for retaining
water. In the Amazonian fish a very sensitive network of nerves
spreads over this marsupial pouch, the principal stem of which arises
from a special nervous ganglion, back of the cerebellum, in the
medulla oblongata. This region of the central nervous system is
strangely developed in different families of fishes, and sends out
nerves performing very varied functions. From it arise, normally, the
nerves of movement and sensation about the face; it also provides the
organs of breathing, the upper part of the alimentary canal, the
throat and the stomach. In the electric fishes the great nerves
entering the electric battery arise from the same cerebral region, and
now I have found that the pouch in which the egg of the Acara is
incubated and its young nursed for a time, receives its nerves from
the same source. This series of facts is truly wonderful, and only
shows how far our science still is from an apprehension of the
functions of the nervous system.—L. A.

Footnote 71:

It is a very general habit among the South American Indians to pierce
the nose, ears, and lips with holes, in which they hang pieces of wood
and feathers, as ornaments.

Footnote 72:

See “Expeditions into the Valley of the Amazons,” published by the
Hakluyt Society.

Footnote 73:

This species belongs to one of the subdivisions of the genus
Auchenipterus; it is undescribed, and Mr. Burkhardt has made five
colored sketches of a number of specimens of different sizes, varying
in their markings.—L. A.

Footnote 74:

When I attempted to record my impression of the basin of the Amazons,
and characterized it as a fresh-water ocean with an archipelago of
islands, I did not mean to limit the comparison to the wide expanse of
water and the large number of islands. The resemblance extends much
further, and the whole basin may be said to be oceanic also, in the
character of its fauna. It is true, we are accustomed to consider the
Chromides, the Characines, the Siluroids, and the Goniodonts, which
constitute the chief population of this network of rivers, as
fresh-water fishes; but in so doing we shut our eyes to their natural
affinities, and remember only the medium in which they live. Let any
one enter upon a more searching comparison, and he will not fail to
perceive that, under the name of Chromides, fishes are united which in
their form and general appearance recall several families of the
class, only known as inhabitants of the sea. The genus Pterophyllum,
for instance, might be placed side by side with the Chætodonts,
without apparently violating its natural affinities, since even Cuvier
considered it as a Platax. The genera Symphysodon and Uaru would not
seem very much out of place, by the side of Brama. The genus Geophagus
and allied forms recall at once the Sparoids, with which some of them
were associated by earlier ichthyologists; while the genus Crenicichla
forms a striking counterpart to the genus Malacanthus. Finally, the
genus Acara and their kindred closely resemble the Pomacentroids.
Indeed, had not the fresh-water genera Pomotis, Centrarchus, and the
like, been erroneously associated with the Percoids, the intimate
relations which bind them to the Chromides, and these again to the
marine types mentioned above, would long ago have been acknowledged.
The genus Monocirrus is a miniature Toxotes, with a barbel.
Polycentrus, which is also found in the Amazons, stands nearest to
Acara and Heros; it has only a larger number of anal spines. In this
connection it ought not to be overlooked that these fishes are not
pelagic, like the Scomberoids, but rather archipelagic, if I may use
this word to designate fishes dwelling among low islands. If we
discard the long-prevailing idea of a close relationship between the
Characines and Salmonides, based solely upon the presence of an
adipose fin, we may at once perceive how manifold are the affinities
between the Characines on one hand, and on the other the Scopelines
and Clupeoids, all of which are essentially marine. These relations
may be traced to the details of the genera; Gasteropelecus, from the
family of Characines, is the pendant of Pristigaster among the
Clupeoids, as Chalcinus recalls Pellona. In the same way may Stomias
and Chauliodus be compared to Cynodon and the like; or Sudis and
Osteoglossum to Megalops, and Erythrinus to Ophicephalus, &c., &c. The
Goniodonts may at first sight hardly seem to have any kindred among
marine fishes; but if we take into account the affinity which
unquestionably links the genus Loricaria and its allies with Pegasus,
and further remember that to this day all the ichthyologists, with the
sole exception of C. Duméril, have united Pegasus in one order with
the Pipe-fishes, it will no longer be doubted that the Goniodonts have
at least a remarkable analogy with the Lophobranches, if they should
not be considered as bearing a close structural relation to them. But
this relation truly exists. The extraordinary mode of rearing their
young, which characterizes the various representatives of the old
genus Syngnathus, is only matched by the equally curious incubation of
the eggs in Loricaria. And as to the other families represented in the
basin of the Amazons, such as the Skates, the Sharks, the Tetraodonts,
the Flat-fishes (Pleuronectides), the Bill-fishes (Scomberesoces), the
Anchovis, Herrings, and other forms of the family of Clupeoids, the
Murænoids, the genuine Sciænoids, the Gobioids, &c., &c., they are
chiefly known as marine types; while the Cyprinodonts occur elsewhere
both in salt and fresh water. The Gymnotines are thus far only known
as fresh-water fishes, nor do I see any ground for comparing them to
any marine type. They cannot be compared to the Murænoids, with which
they have thus far been associated. The only real affinity I can trace
in them is with the Mormyri of the Nile and Senegal, and with the
Notopteri of the Sunda Islands. Eel-shaped fishes are by no means all
related to one another, and their elongated form, with a variety of
patterns, is no indication of their relationship. It may,
nevertheless, be inferred from what precedes, that the fishes of the
Amazons have, as a whole, a marine character peculiarly their own, and
not at all to be met with among the inhabitants of the other great
rivers of the world.

These peculiarities extend to other classes besides fishes. Among the
Bivalve shells, it has long been known that the Amazons nourishes
genera of Naiades peculiar to its waters, or only found besides in the
other great rivers of South America; such as Hyria, Castalia, and
Mycetopus, to which I would add another genus, founded upon slender,
sickle-shaped Unios, common to North and South America. But what seems
to have escaped the attention of conchologists is the striking
resemblance of Hyria and Avicula, of Castalia and Arca, of Mycetopus
and Solen, &c. Thus exhibiting another repetition of marine types in a
family exclusively limited to fresh waters, and having structural
characters of its own, entirely distinct from the marine genera, the
appearance of which they so closely ape. In this connection I cannot
suppress the remark, that it would be puerile to consider such mimicry
as indicative of a community of origin. Some of the land shells even
recall marine forms; such are some of the Bulimus tribe, which
resemble the genus Phasianella and Littorina far more than their own
relatives. The similarity of the fringes of the anterior margin of the
foot is particularly striking. The Ampullariæ remind one also, in a
measure, of the marine genera Struthiolaria, Natica, &c., and many
fossils of the latter family have been confounded with fresh-water
Ampullariæ.

The most noticeable feature of the Amazonian fauna, considered with
reference to its oceanic character, is, however, the abundance of
Cetaceans through its whole extent. Wherever I have navigated these
waters, from Pará, where the tides still send the salt brine up the
river, to Tabatinga on the borders of Peru, in all the larger and
smaller tributaries of the great stream as well as in the many lakes
connected with their ever-changing course, I have seen and heard them,
gamboling at the surface and snoring rhythmically, when undisturbed in
their breathing. At night, especially, when quietly at anchor in the
river, you hardly ever fail to be startled by the noise they make,
when reaching the surface to exhale forcibly the air they have long
retained in their lungs while under water. I have noticed five
different species of this order of animals in the waters of the
Amazons, four of which belong to the family of Porpoises and one to
that of Manatees. Mr. Burkhardt has drawn three of them from fresh
specimens for me, and I hope before long to secure equally faithful
representations of the others, when I shall describe them all
comparatively. One of the Porpoises belongs to the genus Inia, and may
be traced on the upper tributaries of the Amazons to Bolivia, another
resembles more our common Porpoise, while still another recalls the
Dolphin of the sea-coast; but I have been unable to ascertain whether
any one of them is identical with the marine species. At all events,
the black Porpoise of the bay of Marajo, frequently seen in the
vicinity of Pará, is totally different from the gray species seen
higher up the stream.—L. A.

Footnote 75:

As from the beginning our arrangements were made to stay at least a
month in Teffé, it became possible to lay out our work in a more
systematic form than during our rambling travels. It was here that I
secured the largest number of fish skeletons and had several of the
larger animals of the country prepared for the Museum; such as
Manatees, Porpoises, Pirarucus, Sorubims, and the like. I also
undertook here, for the first time, a regular search for the young of
all the species of fishes that could be obtained. Here again my
neighbors, and indeed all the inhabitants of the place, vied with one
another in their efforts to procure specimens for me. Senhor Joaō da
Cunha and Dr. Romualdo made frequent fishing excursions for my
benefit; and when I could not accompany them, a boatful of fish was
nevertheless moored to the shore, in the evening, from which I could
select whatever was useful or interesting. The grocer of the place,
Mr. Pedro Mendez, who employed a skilful fisherman daily to supply his
large family, gave directions that all the fishes caught should be
brought in, and before the kitchen received its provisions, I had my
choice of everything. This was a great favor, especially since the
Indian fisherman, José, whom I had engaged in Manaos to accompany me
through the rest of my journey, was now at Tabatinga, assisting Mr.
Bourget, who had been left there when I returned to Teffé. An old
Passé Indian, who was as familiar with the fishes of the waters as
with the animals of the forest, and whom Major Coutinho had befriended
for many years, rendered also great service in hunting particular
kinds of fishes and reptiles, the haunts of which he alone seemed to
know. The schoolmaster and his boys, in short, everybody who knew how
to catch fish or fowl, was out at work, and, with the assistance of my
young friends Dexter, Hunnewell, and Thayer, and the co-operation of
Major Coutinho and Mr. Burkhardt, our daily progress was unmistakable.
They generally took care of the collections of land animals, while I
reserved the fishes to myself, and Major Coutinho was busy with
geological and meteorological observations. Even the servants helped
in cleaning the skeletons. I made here a very extensive collection of
fish brains, embracing most genera found in this locality, but it was
unfortunately lost on arriving at Manaos. Aware of the difficulty of
transporting preparations so delicate, I kept them always by my side,
simply packed in an open barrel, in the hope of bringing them safely
home, and also that I might, without difficulty, add to the number. In
an unguarded moment, however, while landing, one of our attendants
capsized the whole into the Rio Negro. It is the only part of my
collections which was completely lost.

After setting my whole party well under way in Teffé, I made the very
instructive excursion with Major Estolano, of which an account is
given in the text, to the Lago do Boto, a small sheet of water, by the
side of his sitio on the banks of the main course of the Amazons,
where I had a fair opportunity of ascertaining how widely different
the fishes may be that inhabit adjoining faunæ in the same
hydrographic basin. To this day I have not yet recovered from my
surprise at finding that shores which, from a geographic point of
view, must be considered simply as opposite banks of the same stream,
were, nevertheless, the abode of an essentially different
ichthyological population. Among the most curious fishes obtained
here, I would mention a new genus, allied to Phractocephalus, of which
I know only a single very large species, remarkable for its uniform
canary-yellow color. Doras, Acestra, Pterygoplichthys, &c., were
particularly common. Small as this lake is, the largest animals known
in the whole basin are found in it: such as Manatees Botos,—the
Porpoise of the Amazons, which has given its name to the lake,
Alligators, Pirarucus,—the Sudis gigas of systematic writers;
Sorubims, the large flat-headed Hornpouts; Pacamums, the large, yellow
Siluroid above alluded to, &c., &c.—L. A.

Footnote 76:

It was Cuvier who first ascertained that the small Hyrax belongs to
the same order as the elephant.