CHAPTER XVI

OBSERVATIONS ON THE ZOOLOGY OF THE AMAZON DISTRICT.

A. Mammalia.

Notwithstanding the luxuriance of the vegetation, which might be supposed to afford sustenance, directly or indirectly, to every kind of animal life, the Amazon valley is remarkably deficient in large animals, and of Mammalia generally has a smaller number both of species and individuals, than any other part of the world of equal extent, except Australia. Three small species of deer, which occur but rarely, are the only representatives of the vast herds of countless species of deer and antelopes and buffaloes which swarm in Africa and Asia, and of the wild sheep and goats of Europe and North America. The tapir alone takes the place of the elephants and rhinoceroses of the Old World. Two or three species of large Felidæ, and two wild hogs, with the capybára and páca, comprise almost all its large game; and these are all thinly scattered over a great extent of country, and never occur in such large numbers as do the animals representing them in other parts of the world.

Those singular creatures, the sloths, the armadilloes, and the ant-eaters, are very generally distributed, but only occur singly and sparingly. The small agoutis are perhaps rather more plentiful; but almost the only animals found in any numbers are the monkeys, which are abundant, both in species and individuals, and are the only mammalia that give some degree of life to these trackless forests, which seem peculiarly fitted for their development and increase.

I met with twenty-one species of these animals, some of which I had no opportunity of examining. Several others exist; but it is necessary to reside for some years in each locality, in order to meet with all the different kinds. I subjoin a list of the species, with the localities in which they were found.

MONKEYS FOUND ON THE AMAZON AND THE RIO NEGRO.

Of the above, the first seven have prehensile tails, a character only found among the monkeys of America. The howlers, forming the genus Mycetes, are the largest and most powerful. They have a bony vessel situated beneath the chin, and a strong muscular apparatus in the throat, which assists in producing the loud rolling noise from which they derive their name, and which appears as if a great number of animals were crying in concert. This, however, is not the case; a full-grown male alone makes the howling, which is generally heard at night, or on the approach of rain.