17cS Mr. W. Stone on Moult 



C'ti'i'cted ill this way — for the nincli narrower claim that the 

 change occurs iu some i'eatliers of some individuals of certain 

 species. 



On the other hand it has now been ih' in on si rated that at 

 least many (and apparently all) individuals of every species 

 of bird in Eastern North America wbicli undergoes a spring 

 change of plumage accomplish that change by a moult. If 

 the same thing is not true of European birds, wc liave 

 certainly a strange state of atfairs ! 



Now let us consider the manner in which in\estigatioiis 

 liave been carried out. It should be thoroughly understood, 

 in the first place, that the study of moult or plumage-cliange 

 is one of the most difiicult hranches of ornithology, and 

 requires much pains and constant care to prevent our 

 jumping to conclusions i!ot >varranted by the evidence. 



Tlie papers so far published against the colour-change 

 theory by Mr. Cha})man, Dr. Dwight, and myself are based 

 npon a careful examination of thousands of specimens, many 

 of them ill various stages of moult; while the numbers and 

 data of the individual skins upon which our conclusions are 

 based are recorded, togetber with the actual condition of tbe 

 feathers. 



Mr. Bonbote's paper is notably lacking in these respects, 

 and he gives us his conclusions without placing the evidence 

 before us. For example he states '' From the head oi Larus 

 ridihundus I have taken at the same time new brown feathers 

 and old feathers in tite process of change^' [italics mine]. 

 What he really took were no doubt particoloured feathers 

 which he thovght were clianging, but which we on the other 

 hand think ivere alirays particoloxred from the time they 

 broke from the sheath, and would remain so until they were 

 shed. 



From this example it will be seen that the main difference 

 between us is a difference of interpretation of what we see in 

 the specimens examined. 



Now as to Avhat has l)een proven. I claim that any one 

 who carefully studies the articles by Messrs. Chapman, 

 Allen. Dviight, and myself must admit that we have proved 



