ly fit, and the younger one has made notable progress in assuming his adult coloration of head and throat. When rescued he had only small flecks of red here and there on throat and crown, now it is almost continuous and flares bril- liantly. The change seems to have occurred without any moulting of feathers whatever. Now the red is flecked with gray and pre- dominates in area. This "red" of crown, sides of head, throat and gorget, various- ly referred to in the literature as lilac crimson, purplish red, metallic pink, rose, rose-purple, basically, with metallic re- fections of different hues and in certain lights: black, is im- possible to analyze accurately without color charts. However, on both birds, according to angle of incident light and angle at which it is viewed, the "red" area may be seen as black, emerald green, golden and bronzy green, golden orange, scarlet and crim- son in part or as a whole, or as any of the hues first mentioned. (A Rufous hummer was seen near the cage at 9 A.M.). At 9:10 Rhody was still at his post, still unwilling to sing, though he did cry inaudibly and then rattle-boo. At 9:30 he was gone; but at 9:40, the wrentits notified me that he was to be found at the glade. Accordingly I found him there working at nest 3-37. At 10:30 he was still working there. I then went to the cage and sat down inside. R5 was composed and friendly. At 10:40 Rhody came and posted himself at the wire. R5 had instantly retreated up into his hiding place in the acacia branch. Rhody remained where he was 12 minutes, most of the time keeping perfectly still except to cock an eye up occasionally in R5's direction. I doubt if he could see that bird, but it seemed evi- dent that he knew where he was, or at least where he should be. Nevertheless, in a few minutes, he trotted off along the path leading to the corner where he had had R5 at his mercy yesterday and began a careful scrutiny of everything in the vicinity. With the exception of yesterday I had never seen him there before. After a few minutes he turned his back to the corner, rattle-booed (from a sense of frustration?) came out, summed himself for a few minutes, then went back to work on nest 3-37. Now these notes have cited instances and/or have referred to actions upon the part of Rhody, Archie and Terry, where each has returned to search again at a spot from which a mouse or a lizard has been seen to run, even after he had discovered the new location of the animal. And in some cases, search has been renewed in the first location even when the quarry was in plain sight elsewhere and positively known to be there by the bird. This same thing happened also with R5, day before yesterday, with a mouse in the cage, but it was not recorded. As a mere guess: The bird retains something equivalent to recol- lection of the mouse's having been under a certain rock, sees it escape, fails to catch it and returns to the original rock, having been unable to understand that the mouse, having escaped, is no longer there and can only be found in the new place. His mental picture of the occurrence is confused, if he has one; he is unable to associate the mouse in its new location with it in its old one. Perhaps it has become two mice. Now Rhody, in going back to the corner to look for R5 (as I think was his purpose) seems to have shown the same inability to analyze and correlate events in the case of R5, that he and other road-runners have exhibited in the mouse and lizard episodes. At 11:55 Rhody was still working at 3-37, but when I went to