(30) grosser human ear, or, as often appears to be the case, as these notes record, the strokes of the bill keep visible time to his song. Mimicry of motion. This afternoon one was digging near me when the other ran up to him quickly, stood in front of him face to face, peered down into the hole and imitated the swinging motion of the other in exact synchronism without, however, attempting to interfere--a curious sight. Green-eyes, who was doing the digging, at first paid no attention to this mockery, but finally had enough of it and gave the other a combined peck and push, whereupon the performance ceased. None of this appeared to arouse any real resentment on the part of either bird. March 5th. This morning I made a short ladder so that I could look into the nest easier, but deferred placing it as one of the birds was sitting quietly in the nest. It remained there for an hour or more and I then looked for eggs, but there were none. Visitors hear flicker imitation. Arrival of visitors prevented further observations for some time. As they were leaving about 4 o'clock one of the birds broke out into full song, in which, at one time, the call of the flicker was so exactly reproduced that my visitors commented on . 4:07. Went out to complete the ladder job, but one bird was sitting quietly in the nest, so the job was postponed. I am hoping that I shall be able to identify the author of the eggs, if any. More visitors came, so I was further delayed. 5:30 The visitors have left. I went out and finished the job, then climbed up the ladder to find a bird on the nest, so as I did not care to disturb it (It had gone into it while I was working there) I did not investigate and it was too dark inside the tree to determine which bird it was. (Mr. Brock says that birds usually lay their eggs in the morning. One each morning until the set is finished). The bird was not disturbed by my peering into the nest.