1504. (It will be remembered that he had no mouse yesterday). This is the first time that Rhody has been seen to run at high speed to the mousery and, at the same time, the first instance of his having been seen to lead the way there, in effect, without pausing to observe if he were being followed.* That is: to assure himself that the contemplated programme would be carried out. The suggestion here then, is that he has advanced another stage in learning to such effect that, in this instance at least, he un- hesitatingly omitted still another element as being non-essential in his going-to-the-mousery pattern. The real explanation, of course, may be something entirely different. August 17th. No changes of consequence were noted in the behavior of any of the birds under observation. Rhody's Roosting Time and Place checked up. About 5:15 P.M. Rhody started for his night roost, and I decided to check up on him, as this has not been done for a long time. He followed his usual route, including his regular deviation from the shortest line to look at the cars in front of the Scamell house. He reached the ladder tree at 5:28 and, at 5:34½ pre- cisely, jumped across to the roost tree and went at once into his house, lying down immediately. (Clear, warm, calm; Sunset 7:01 ). He does like this house. From the street below ( I have not climbed the tree for a closer inspection) his addition to the structure (his house-nest) appears neat and compact. It forms a sort of low parapet around the floor, over which his head can be just seen. Effect of Banding Upon Okii and Chiisai. These birds have now been banded for about 48 hours. (7:30 P.M) The effect, to date, upon them is striking. In the first place it has entirely changed their usual gate in walking or running. In walking-now-the banded foot is raised higher than the other one and more rapidly, and both hops and jumps have been introduced to an extent not usually seen in thrashers. (By hop I mean taking off on one foot and landing on the same foot By jump I mean taking off on both feet and landing on either one or both feet. Popularly, a bird is said to hop when it is in reality jumping). In running the same effect is noted and also a tendency to eer off the course. Curiously, the effect upon the observer is such as is apt to lead him astray, in that he may attribute the action observed either to the birds' being partly crippled (which in effect is really the case) or to exuberance of spirits (which is almost exactly what it isn't). These effects are not surprising, except as to magnitude. The unequal distribution of weights throws the birds out of both static and dynamic equilibrium. Although the weight of a band is small as compared to the weight of the bird, it must be fairly large as compared with the weight of the foot. It is well know that some defects in the action of a horse may be corrected by placing relatively trivial weights at the proper places on his feet. An effect has been noted, however, that is surprising , and that is that the birds now are inclined to depart from the standard thrasher practice of going from place to place on foot, and fly instead. So pronounced is this tendency that they (especially Chiisai) may fly between two points on the ground that are not more than 3 or 4 feet apart.