No note came to encourage me, but, gazing steadily upward, after a time I noticed something that looked like a fly running along the wall. Bringing my glass to my eyes, I found that it was a bird, and one of the white-throated family I so longed to see. She--for her silence and her ways proclaimed her sex--was running about where appeared to be nothing but perpendicular rock, flirting her tail after the manner of her race, as happy and as unconcerned as if several thousand feet of sheer cliff did not stretch between her and the brook at its foot. Her movements were jerky and wren-like, and every few minutes she flitted into a tiny crevice that seemed, from my point of view, hardly large enough to admit even her minute form. She was dressed like the sweet singer of yesterday, and the door she entered so familiarly was the same I had seen him interested in. I guessed that she was his mate. The bird seemed to be gathering from the rock something which she constantly carried into the hole. Possibly there were nestlings in that snug and inaccessible home. To discover if my conjectures were true, I redoubled my vigilance, though it was neck-breaking work, for so narrow was the cañon at that point that I could not get far enough away for a more level view. Sometimes the bustling little wren flew to the top of the wall, about twenty feet above her front door, as it looked to me (it may have been ten times that). Over the edge she instantly disappeared, but in a few minutes returned to her occupation on the rock. Upon the earth beneath her sky parlor she seemed never to turn her eyes, and I began to fear that I should get no nearer view of the shy cliff-dweller. Finally, however, the caprice seized the tantalizing creature of descending to the level of mortals, and the brook. Suddenly, while I looked, she flung herself off her perch, and fell--down--down--down-- disappearing at last behind a clump of weeds at the bottom. Was she killed? Had she been shot by some noiseless air-gun? What had become of the tiny wren? I sprang to my feet, and hurried as near as the intervening stream would allow, when lo! there she was, lively and fussy as ever, running about at the foot of the cliff, searching, searching all the time, ever and anon jumping up and pulling from the rock something that clung to it.