listening to all sounds, far and near. I am reasonably certain that he listens for sounds from within the wall. When working from the top his method is similar in general, but has one specific exception, due to changed conditions. Thus, in order to scrutinize the face of the wall and, at the same time take advantage of the fact that he is now invisible from its face, he sneaks up with great deliberation to peer down over the rim. As he approaches the edge, he very slowly lowers his head and rolls his eyes downward to their utmost extent in an effort to see if there is anything of interest there, with minimum exposure of his own person. Gradually he thrusts his head further and further forward, moving it from side to side so as to miss nothing. When he discovers that there is not, which is usually the case, he straightens up and scans the general surroundings--bushes, trees, etc. On one such occasion during this observation period he caught sight of an Anna humming-bird sitting on a low limb of an apple tree. He immediately flattened down to the ground like a cat and began a slow stalk of the bird 15 feet away, maintaining this crouching attitude. When within about 5 feet, the hummer, who had been fully aware of approaching events, buzzed off. R straightened up and resumed his examination of the wall--this time from the path. He included in his survey also the wall where I was sitting. As I felt sorry for him in his failure to get a lizard (though delighted with the bird fiasco) I dropped him a worm or two, whereupon he lay down comfortably in convenient hollow which fitted him nicely and disposed himself to receive future favors. Here, however, his expectations did not coincide with my plans. The humming-bird episode had looked as if he were really hungry and wanted the bird as food. I hoped, by waiting, to get some additional evidence on this point, such for example, as a renewed and intensive search for food on his own initiative, or an attack on the two wren-tits