mate, who kept doggedly on his trail. I have now watched the behavior of this same pair of thrashers through five nesting periods and am now in the sixth, but have not seen the slightest approach to this line of action before today. It is inexplicable to me. While I assume that it is part of the mating complex--why has it not occurred before? Superficially it looks exactly as if Greenie were trying to drive Brownie away, though there has been no coming to blows. Since 8:30 A.M. neither bird was seen to visit the nest or even look in its direction. If their actions are performed in accordance with some definite pattern, which, I understand, the pundits insist is the case, then the key to this one is assuredly not yet within my grasp. I refer not to this specific pair of series of events alone, but to the life pattern of this birds. If there is such a thing, one would expect it to be developed fully (as far as nesting is concerned) with one nest, and thereafter repeated indefinitely with each succeeding nest. Most assuredly, again, if there is a pattern, it is not too much to expect, that with the same class appears not to be the case; unless this same thing occurred last year and I failed to detect it--which is unlikely. At present the simplest explanation seems to be: that either these birds have no pattern (and I have never thought that they ever followed one except perhaps in a general, loose sort of way) or else that they do have one, but that it is not completely revealed in a year's time. In the latter case, then, today's behavior might mean anything. Pattern theory must be applied with discrimination. With a stupid bird, I can see that the idea of a pattern, may be a good guide to the understanding of behavior; but with an intel- only ligent one, I think (and this is not based on today's observations) if rigorously followed, it can lead to as much perplexity as the