THE AMAZON DISTRICT. 325 



supply the Indians with the greater part of their animal food, 

 and are at all times more plentiful, and easier to be obtained, 

 than birds or game from the forest. 



During my residence on the Rio Negro I carefully figured 

 and described every species I met with ; and at the time I left 

 fresh ones were every day occurring. The soft-finned fishes 

 are much the most numerous, and comprise some of the best 

 kinds of food. Of the Siluridce I obtained fifty-one species, of 

 Serrasalmo twenty-four, of Chalceus twenty-six, of Gymnotas 

 ten, and of spinous-finned fishes (Acanthopterygid) forty-two. 

 Of all kinds of fishes I found two hundred and five species in 

 the Rio Negro alone, and these, I am sure, are but a small 

 portion of what exist there. Being a black-water river, most 

 of its fishes are different from those found in the Amazon. In 

 fact, in every small river, and in different parts of the same 

 river, distinct kinds are found. The greater part of those 

 which inhabit the Upper Rio Negro are not found near its 

 mouth, where there are many other kinds equally unknown in 

 the clearer, darker, and probably colder waters of its higher 

 branches. From the number of new fishes constantly found 

 in every fresh locality and in every fisherman's basket, we may 

 estimate that at least five hundred species exist in the Rio 

 Negro and its tributary streams. The number in the whole 

 valley of the Amazon it is impossible to estimate with any 

 approach to accuracy. 



D. Insects. 



To describe the countless tribes of insects that swarm in the 

 dense forests of the Amazon would require volumes. In no 

 country in the world is there more variety and beauty ; nowhere 

 are there species of larger size or of more brilliant colours. 

 Here are found the extraordinary harlequin-beetle, the gigantic 

 Prioni and Dynastes ; but these are exceptions to the great 

 mass of the Cokoptera, which, though in immense variety, are 

 of small size and of little brilliancy of colour, offering a great 

 contrast to the generally large-sized and gorgeous species of 

 tropical Africa, India, and Australia. In the other orders the 

 same rule holds good, except in the Hymenoptera, which con- 

 tain many gigantic and handsome species. It is in the lovely 



