If one asks the Indians why this incessant noise and disturbance arises on particular nights, they answer, with a smile, that “the animals are rejoicing in the bright moonlight, and keeping the feast of the full moon.” To me it appeared that the scene had probably originated in some accidental combat, and that hence the disturbance had spread to other animals, and thus the noise had increased more and more. The jaguar pursues the peccaries and tapirs, and these, pressing against each other in their flight, break through the interwoven tree-like shrubs which impede their escape; the apes on the tops of the trees, being frightened by the crash, join their cries to those of the larger animals; this arouses the tribes of birds, who build their nests in communities, and thus the whole animal world becomes in a state of commotion. Longer experience taught us that it is by no means always the celebration of the brightness of the moon which disturbs the repose of the woods: we witnessed the same occurrence repeatedly, and found that the voices were loudest during violent falls of rain, or when, with loud peals of thunder, the flashing lightning illuminated the deep recesses of the forest. The good-natured Franciscan monk, who, although he had been suffering for several months from fever, accompanied us through the Cataracts of Atures and Maypures to San Carlos on the Rio Negro, and to the Brazilian boundary, used to say, when fearful on the closing in of night that there might be a thunder-storm, “May Heaven grant a quiet night both to us and to the wild beasts of the forest!”