territoriality--but the following is merely a speculation, since there are too many assumptions in the foregoing data and not enough in the way of rigorously verified facts. However, it looks like this: Neo and mate at home announcing territory occupied and the two birds mated. The bird from the north: Inver hypothetically, comes to the No-man's land between his and Neo's territory and even encroaches upon the latter, but does not penetrate far enough toward the inner sanctuary to stimulate Neo into repulsing him. Inver's mate--or if not actually "married", at least a follower, companion, comes, joins him. He is satisfied that the territory is well defended and goes back to the territory which was, at one time, actually that of a bird known as Inver and with whom Neo, in seeking to establish himself in the territory (here) vacated by the death of its former owner, Brown- ie, fought last year (as described in these notes). On the departure of this bird Neo stopped singing, but then turned his attention to Brokenwing's announcements from his terri- tory. After singing from the ironwood for a few minutes, his song stopped, and he is believed to have gone down into the broad No-man's land between his and BW's territory--judging only by sounds heard. N2 remained here scripping on his departure (true to form) then was seen to sail down toward that territory. Dux et Comes. The words Dux and Comes (leader and follower) have been intro- duced above without explanation; the idea being that these terms are appropriate as applied to two birds that are much in each other's company; where the actually relationship between them (as a mated pair or as parent and young) has not been definitely established and where one of them is very clearly a follower of the movements of the other, plainly playing a role inferior to it, in a restricted sense. In the case of Neo and N2 (or Longtail) Brokenwing and Long- bill the relationship is known: they are mated pairs. In the case of the supposed Inver and his comes the exact relationship is unknown, although it is almost certain that they are paired. Perhaps we can designate them temporarily as Dux 1 and Comes 1. At 11:30 Rhody indicated that he wanted another mouse. I had expected him to show this sooner, as the first one was very small. He was given another small one and seemed satisfied. I now left, returning at 12 o'clock. Neo was now back in his pine singing loudly. I went there at once. Neo quickly appeared and climbed up to him. Before she reached him I had caught some of his phrases: Wick-up, wick-up............ (Flicker calls). Pitti-churk, pitti-churk......Usually three successively. Choorie, chereet, cherit' Pit tse-e-e-e-e-e-e-e Pick' (or pick). On her arrival the song changed, not only in that the above phrases were dropped, but that all the rest of the song was changed. New phrases detected were now: Berry- cawp, berry-cawp, ............ and: