Surprise has often been expressed that the common chipping sparrow can so neatly curl a long horse-hair into the lining of its little nest. It cannot be explained, perhaps, but we have at least a clue to it. One end of the hair is snugly tucked in among stouter materials, and then,—I ask the question only,—as the bird coils it about the sides of the nest with its beak, does it break or dent it, or is there some chemical effect produced by the bird’s saliva? The hairs do not appear to be merely dry-curled, for in that case they would unroll when taken from the nest, and such as I have tried, when just placed in position, retained the coiled condition when removed. But old hair, curled by long exposure to the air and moisture, is often used, and this is far more tractable. When we come to examine woven nests, such as the Baltimore oriole and the red-eyed vireo, as well as some other small birds, build, there is offered a great deal more to study, for how they accomplish what they do, with their only tools their feet and beak, is not wholly known. That the tropical tailor-bird should run a thread through a leaf and so bring the edges together and make a conical-shaped bag, is not so very strange. It is little more than the piercing of the leaf and then putting the thread through the hole. This is ingenious but not wonderful, because not difficult; but let us consider a Baltimore oriole and his nest. The latter is often suspended from a very slender elm or willow twig, and the bird has a hard time to hold on while at work. One experienced old oriole has for years built in the elm near my door, and occasionally I have caught a glimpse of him. I will not be positive, but believe that his first move is to find a good stout string, and this he ties to the twig. I use the word “tie” because I have found in many cases a capitally-tied knot, but how the bird, or birds, could accomplish this I cannot imagine. Both feet and beak, I suppose, are brought into play, but how? To get some insight into the matter, I once tied a very long string to the end of a thread that the oriole had secured at one end and left dangling. This interference caused some commotion, but the bird was not outwitted. It caught the long string by its loose end and wrapped it over and over various twigs, and soon had a curious open-work bag that served its purpose admirably. The lining of soft, fluffy stuff’s was soon added. This brought up the question as to whether the bird ever ties short pieces together and so makes a more secure cable that gives strength to the finished nest. In examining nests, I have seen such knots as might have been tied by the birds, but there was no way to prove it. That they do wrap a string several times about a twig and then tie it, just as a boy ties his fishing-line to a pole, is certain. With my field-glass I have followed the bird far enough to be sure of this. When at work, the bird, from necessity, is in