and Culonr-chanijc in Biri/.f. \79 



that certain iiiflividuals (we claim by inference all indi- 

 vidnals) of the many species tliat we have examined accom- 

 plish the spring change of plumage by a moult, and that the 

 feathers of the nuptial dress which are alleged to have 

 undergone a change of pigment burst from the pin-feather 

 sheaths exactly the same, so far as colour is concerned, as 

 tliey are in the breeding-bird. Furthermore, did oppor- 

 tunity offer to demonstrate our views personally to our 

 critics with our series of specimens, I am sanguine enough 

 to think that they wonld agree with us. One of the 

 principal difficulties attaching to the study of moult is 

 the lack of satisfactory material, and this I think has in 

 many cases led Mr. Bonliote and others astray. Few col- 

 lectors liave preserved moulting birds, because they make 

 such ragged specimens ; and in niy own experience it has 

 often happened that while I have had scores of examples at 

 hand, not one of them showed traces of the moult that I 

 snspected must take place. Nevertheless, the existence of 

 the moult was always demonstrated when an effort was 

 made to secure specimens at the proper time of year. Have 

 such efforts been made to secure spring-moulting examples 

 of European birds in cases where it is contended that no 

 moult occurs, and, if so, has not the investigator been forced 

 to admit tlmt j^nrt of Ihe plumar/e at least was moulted ? 



An examination of our pnpers mentioned above will, I 

 consider, also force the admission that every fact so far 

 recorded as observed in a prepared specimen or dead bird is 

 entirely in accordance with the theory of a spring moult, 

 and can be quoted more logically as an argument for moult 

 than for the theory of direct change of pigment. 



Mr. Bonhote, while admitting a spring moult in many 

 birds, says : " It does not follow that, because a bird is 

 moulting, a colour-change in individual feathers, be they 

 old or new, is thereby excluded." Very true ; if we prove 

 that ninety-nine feathers break from the sheath just as they 

 are in the nuptial dress, we may not be able to prove that 

 the hundredth does not undergo a change, and it is mani- 

 festly out of the (jucslion to demonstrate how every individual 



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