204 The Irish Naticralist. [August, 



much for the evidence beiug in favour that the " frill" is 

 ornamental in function. But we still ask, why do these orna- 

 mental feathers vary so much ? Without making any 

 assumptions this question is a most difficult one to answer. 

 Wallace points out that constanc}^ of colours maybe explained 

 on the principle of protective colouration. The females 

 require this more for hatching, &c. Hence they are more 

 sombre plumed. Hence we may argue that where protection 

 is actually unnecessary and even injurious in the economy 

 of nature, coloration may become inconstant and even 

 varied. This is, in part, advocating Stolzmann's^ views. 

 According to him it is often advantageous that many male 

 birds be destroyed by their natural enemies, more especially 

 if polygamous, because the females^ when hatching, may be 

 disturbed by a male which has not found a mate. Now, 

 inasmuch as the male Ruffs seldom injure each other in battle, 

 and so their numbers are not diminished, and moreover they 

 aspire to keeping many wives, I maintain that the result must 

 be that many males never get the chance of mating. Hence 

 in reality, in the economy of nature there are a number of 

 superfluous males. They require to be destroyed, and so 

 natural selection, which only attends to the preservation of 

 species, ceases now to act. Thus the male plumage, no longer 

 conservative in colour for any protective purpose, may undergo 

 a considerable amount of variation. It is worth suggesting 

 that age may also have something to do with the variation in 

 the nuptial plumage. The excitable, highly- strung, polj-gamous 

 nature of Ruffs may have brought about a plumage change 

 comparable to w4iat takes place in a much less marked degree 

 among other waders normally as age advances. 



Thompson- states that when visiting the London Zoological 

 Gardens, Regent's-park, in 1833, the Keeper, Mr. Hunt, in- 

 formed him that a bird in captivity for two or three years 

 assumed a different " ruff" each summer. Mr. R. Ball noticed 

 the same in the Dublin Zoological Gardens. He states that 

 a Ruff received in full plumage changed twice. Montagu and 

 Bartlett,^ on the contrary, maintain that the nuptial plumage 



^ Proc. Zool. Soc, 1S85. 



= "Nat. Hist, of Ireland," vol. ii., p. 233. 



3 Yarrell " British Birds," vol. iii., p- 433- 



