keep it in sight. All my caution and all recollection of what the Indians had said was now forgot, so great was my interest in this bird-army; but as they moved on without pause they quickly left me behind, and presently my career was stopped by an impenetrable tangle of bushes, vines, and roots of large trees extending like huge cables along the ground. In the midst of this leafy labyrinth I sat down on a projecting root to cool my blood before attempting to make my way back to my former position. After that tempest of motion and confused noises the silence of the forest seemed very profound; but before I had been resting many moments it was broken by a low strain of exquisite bird-melody, wonderfully pure and expressive, unlike any musical sound I had ever heard before. It seemed to issue from a thick cluster of broad leaves of a creeper only a few yards from where I sat. With my eyes fixed on this green hiding-place I waited with suspended breath for its repetition, wondering whether any civilised being had ever listened to such a strain before. Surely not, I thought, else the fame of so divine a melody would long ago have been noised abroad. I thought of the rialejo, the celebrated organ-bird or flute-bird, and of the various ways in which hearers are affected by it. To some its warbling is like the sound of a beautiful mysterious instrument, while to others it seems like the singing of a blithe-hearted child with a highly melodious voice. I had often heard and listened with delight to the singing of the rialejo in the Guayana forests, but this song, or musical phrase, was utterly unlike it in character. It was
