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one dress and one sex, it is necessary first to investigate whether there are not two distinct forms 

 of ' Kypeorre ' — the one bred between Tetrao tetrix (<3) and Lagopus alius ( ? ), the other between 

 Lag opus albus (6) and Tetrao tetrix ( ? ). 



" A similar hypothesis, as previously mentioned, has been started to account for the parentage 

 of the Rakkelhane ; but the argument proving its fallacy with that form of hybrid, holds equally 

 good as regards the 'Rypeorre.' Now it is an established fact that all individuals of the 

 Rypeorre-hybrid, if procured at any given season of the year, are singularly alike both in size 

 and coloration of plumage ; and hence their origin surely cannot be traced to more than one of 

 the two possible connexions. 



"As previously stated, the exertions of Swedish sportsmen and naturalists have provided 

 ample proof of the true parentage of the Eakkelhane. On one occasion eggs taken from a 

 sitting Tetrao urogallus (?) were incubated by a Domestic Hen, the issue being a brood of 

 Rakkelhanes. Such a fact, taken in connexion with the similarity of appearance presented by all 

 individuals of the Rakkelhane-hybrid, renders further evidence superfluous. 



" So direct a proof of the Rypeorre has not yet been obtained ; and it must therefore be 

 inferred from less conclusive facts. 



" Nilsson having suggested (in his ' Ornithologia Suecica,' vol. i. p. 303) the probability of the 

 Rypeorre-hybrid being bred ' a T. tetrice patre et Tetr. subalpino femina,' the conjecture has from 

 that time to this remained unchallenged. By reason of his fine plumage, elegant form, and excess 

 of vitality, Tetrao tetrix (d 1 ) has been able to form these alien connexions. No other evidence, I 

 believe, has been advanced in proof of the assertion but the fact that female Ptarmigan are said 

 sometimes to make their appearance at the ' Aarfuglelege ' (pairing-haunts of black game). 



" On closer inspection, this theory of parentage does not appear to be in strict accordance 

 with fact. Nay, the origin of the ' Rypeorre ' can, I maintain, with far greater probability be 

 explained as the result of Lagopus albus (6) pairing with Tetrao tetrix ( ? ). 



" This view has, indeed, been formerly entertained in a few instances, but found little favour 

 with naturalists. The following are the chief arguments that have led me to adopt it. 



" It is well known that the Rakkelhane ( 6 ) greatly exceeds its male parent in size, whereas, 

 in that respect, it exhibits a perfect resemblance to its mother. Now, reasoning from analogy, 

 the size of the male Rypeorre should correspond exactly with that of its supposed mother [Tetrao 

 tetrix ? ), and exceed that of its supposed father [Lagopus albus <5 ) in due proportion. And 

 this, indeed, is found to be the case. That the female Lagopus albus should generate the large- 

 sized, strong-limbed Rypeorre is every whit as improbable as that Tetrao tetrix (?) can be the 

 mother of the Rakkelhane. The coloration, too, of the parent birds favours, I think, the assump- 

 tion. That the Tetrao urogallus (?) should pair with the Blackcock, which, though smaller in 

 size, resembles even closely her proper male in plumage, is not surprising ; but that the female 

 Ptarmigan should pair with the Blackcock, a bird so different in appearance from her true mate, 

 is not so easy to explain. 



" On the other hand, it is far from improbable that a young Greyhen which has never 

 paired should yield in a moment of surprise to the amatory advances of a male Ptarmigan in his 

 dark-coloured summer dress. 



" It has long been known that Ptarmigan will repair to the breeding-haunts of black game ; 



