The universal geography : earth and its inhabitants

FAUNA OF AMAZOXLV. 107
type. But on the other hand there are 38 memhers of the monkey family,
all climbers and all with prehensile tails. The cercohpfes, a species of bear, is also
of exclusively arboreal habits, and of the four kinds of ant-eaters [myrmecojjharjn)
studied bj-^ Bates, three live in the trees, as do also the degenerate descendants of
the colossal megatherium (sloth), besides various squirrels, snakes, and other
reptiles.
Gulls and the frigate-bird ascend the Amazons to the Peruvian plains 2,500
miles from the sea, while the manatee and dolphins frequent all the large affluents
as far as the first rapids. But the various species of cetaceans have acquired
exclusively fluvial forms. The water boa (eiiiiecfes miiriiii(s), which sometimes
attacks man, acquires enormous proportions in the Napo basin, where Osculati saw
one which appeared to him some 50 or 60 feet long.
The Amazons waters are infested by the formidable j'acare uassti, or great
crocodile ; but the turtle, which formerly swarmed in the main stream, has been
nearly exterminated or driven up the aflluents bj' the reckless destruction of its
eggs. Both of these animals withdraw to the lakes and tributaries during the
rainy season, returning in the dry period, or else burying themselves in the mud
during the summer months. Saurians and fishes of identical species vary in colour
according to the darker or lighter tints of the fluvial waters frequented by them.
All the running waters teem with fishes, and the 600 or 700 species estimated
by Spix were raised by Apiassiz to nearly 2,000 for the Amazons alone, that is,
twice as many as in the Mediterranean, and more than in the whole Atlantic. The
Hyanuary lagoon west of the Rio Negro confluence contains over 200, or more
than all the rivers and lakes of Europe together. Some are extremely ferocious ;
the pira/i/ias {tefrafjonopteruH), despite their small size, attack man with great fury,
and often snap off the lips of dogs and horses drinking in the streams infested by
them.
Although poor in some bird forms, notably humming birds, Amazonia abounds
in others, and Wallace alone collected over 500 different kinds. Aquatic beetles
are rare, but on the other hand no less than 700 species of butterflies occur within
a radius of four miles round Para. It was the extreme variety of the lepidoptera
that enabled Bates to prosecute those comparative studies on transformation and
mimicry that supplied so many arguments in support of Darwin's theory on the
Origin of Species. Some of the winged pests, such as the nocturnal mosquito and
the pium or day fly, render certain riverside districts in the Purus valley quite
uninhabitable ;
the sauba ant also {cecodoma cephalotes), which lines its imderground
galleries with leaves, makes all tillage impossible in many places. Coffee planta-
tions laid out at great cost have been utterly destroyed by its invading hosts. The
galleries, which extend to a distance of 160 and even 200 feet, are the work of a
delving population provided with a frontal eye like the fabulous cyclops or the
modern miners with their Davy lamps. A denizen of these subterranean abodes
is the amphisbcena, " mother of the saubas," a harmless snake said by the natives
to have two heads. Even more dreaded than the sauba is the formiga do fogo, or
" fire-ant " Onyrmica rubra), which has at times put whole communities to flight.