TANYSIPTERA RIEDELI. I77 



have nothing to do with fishes ; and Mr. Wallace, quoted by Mr. Sharpe, 

 speaks of the Kinghunters (^Dacelo) of Australia. 



But concerning the tail and its peculiar termination I recommend a 

 perusal of Mr. Osbert Salvin's article (P. Z. S. 1873, p. 429) on the tail- 

 feathers of Momotus. This article is illustrated by examples of tails in process 

 of becoming spatulate, and gives a letter from Mr. A. D. Bartlett, in which he 

 says, " 1 have seen this bird [a Motmot] in the act of picking off the webs 

 of the central feathers of its tail. . . . The Motmot frequently threw up 

 castings, after the manner of the Kingfishers and other birds that swallow 

 indigestible substances." 



Mr. Salvin says, after an elaborate argument : — " This character . . . 

 may not be traceable directly to ' sexual selection ;' still it may be that an 

 attractive peculiarity in one sex has subsequently been adopted as equally 

 attractive by the other, and hence the habit of nibbling their tail-feathers 



universally practised by both sexes alike In other birds, such as Steganura, 



Loddigesia, and Discura amongst Humming-birds, similar features prevail, and 

 also in such cases as Prionikirus amongst Parrots and Tanysiptera amongst 

 Kingfishers ; but in these last, as in the Motmots, the character is common 

 to both sexes In Steganura cissura the lateral feathers are simply nar- 

 rowed " Lastly, " Whether the same cause has produced the racket- 

 shaped tails in Prioniturus and Tanysiptera is more difficult to trace, as it would 

 appear that in these birds the rhachis becomes more and more denuded in 

 each successive moult, showing other causes at work." 



These short extracts do no justice to this very interesting article, which 

 should be read. 



I shall not plunge into Darwinism, of which Huxley has given the 

 clearest description. He says, " The Darwinian hypothesis is this : all 

 species have been produced by the development of varieties from common 

 stocks, by the conversion of these, first into permanent races, and then into 



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