1904.] PACKARD— ORIGIN OF MARKINGS OF ORGANISMS. 397 



be quite inadequate and misleading. On the other hand the 

 physical causes we here advocate must be our main reliance in a 

 thoroughgoing and satisfactory explanation of the phenomena of 

 protective coloration. There is nevertheless need of much addi- 

 tional observation and experimentation. 



2. Facts against the Bates Muller Hypotheses, from Obser- 

 vations MADE IN North America. 



For the first time in my life, having for over forty years observed 

 and collected insects, though by no means constantly in the field, 

 I actually saw a bird chase a butterfly. It was with great interest 

 that I watched the procedure both of the bird and butterfly from 

 the piazza of my summer cottage on the shores of Casco Bay, Me., 

 at noon of a bright sunny day early in July, 1901. The aggressor 

 was a black-throated green wood-warbler, the quarry a Pieris, appar- 

 ently Pieris rapcE, then not uncommon about the house. The 

 warbler was seen to dart swiftly after the butterfly, whose flight is 

 very erratic and unsteady. It disappeared after flying a few yards, 

 and as the bird kept on alone in its course, I had good reason to 

 believe that it had caught and swallowed the butterfly. Prof. H. 

 H. Wilder, then living in the next house, at about the same date 

 actually observed one of these warblers eating a Catocala in a path. 

 It ate the body of the moth and left the wings lying on the ground. 

 I also saw one of these warblers chase a Catocala around an elder 

 bush on the edge of my piazza, but did not see that the bird was 

 successful in his pursuit. 



Kingbirds were common about the house and shore, but I did 

 not see any chase the cabbage butterflies, but was interested in wit- 

 nessing one pursue a red-under-wing moth (Catocala). The moth 

 flew in its usual very rapid and zigzag fashion, darting in this and that 

 direction, as usual with species of this genus. The bird in vain 

 tried to seize the saucy moth so secure in its rapid, zigzag, tumbling, 

 headlong flight. The race was maintained for about five hundred 

 feet ; but so far as I could see, for the racecourse led directly from 

 me, the moth escaped scot-free, the kingbird being baffled and 

 outflown. I then realized, as must every one who watches the swift, 

 zigzag, apparently aimless flight of any butterfly, how admirably 

 adapted such a mode of progression is for the preservation of the 

 species. 



