Vol. XVIII 

 190 r 



J Eighteetith Congress of the A. O. U. ^o 



Without the examination of furtlier material I cannot deter- 

 mine definitely the status of knmlieni and fielsoni, but I am of 

 opinion that the former is a plumage of leucopterus after the 

 second postnuptial moult, and the latter is possibly a similar stage 

 of glaucescetis. This question and many others present themselves 

 as we learn what bearing age has in modifying plumage and 

 proportions of the Gulls. I think the specific distinctness of 

 L. barrovianus from g/auci/s is open to doubt, and brachyhy fichus 

 is likely to prove merely a variety of caniis, while Z. sckistisagtis, 

 L. affinis^ L. cachiiiiums and L. vegie, on further study, may 

 perhaps show new affinities. 



My sketch of the sequence of moults and plumages of the Gulls 

 and Terns has necessarily been superficial in many respects, but 

 at least we have gained enough insight into the usual course of 

 their changes of plumage to see that plumages are definite entities 

 acquired along definite lines of development. It seems to me 

 that, with all the material available for study at the present day, 

 we should avoid classing together, as in the' past, unrelated stages 

 of " immature " plumage and specify precisely what stage we mean 

 unless we wish to subject ourselves to the lurking suspicion that 

 our knowledge or our methods have not kept pace with our scien- 

 tific zeal. 



EIGHTEENTH CONGRESS OF THE AMERICAN 

 ORNITHOLOGISTS' UNION. 



The Eighteenth Congress of the American Ornithologists' 

 Union convened in Cambridge, Mass., Monday evening, Novem- 

 ber 12, 1900. The business meeting was held in Mr. William 

 Brewster's museum, and the public sessions, commencing Tues- 

 day, November 13, and lasting three days, were held in the Nash 

 Lecture-room of the University Museum. 



Business Session. — The meeting was called to order by Vice- 

 President Merriam, in the absence of the President, Mr. Robert 



