OBSERVATIONS ON THE G ANNEX. '185 



tremely diminutive, as scarcely to be entitled to 

 that denomination. 



Has not the discovery of a labyrinth in Mergus Cas- 

 tor, of similar appearance to that of M. Merganser, been, 

 considered conclusive, without examining the rest of the 

 trachea ; or may not the female Merganser resemble in 

 plumage both the sexes of the Castor P Has any one 

 yet observed a bird in the plumage of M. Merganser, to 

 be a female ; and are we certain that the young male 

 Mergus serrator, in its immature plumage, has not been 

 confounded with these, since it has been ascertained, that 

 that species is furnished with one enlargement in the 

 trachea? If M. Merganser, in its immature state, 

 should resemble in plumage M. Castor, the trachea of 

 the young males would undoubtedly be similar to the 

 adults, and we should be led still to look for a distinct 

 species in a similar dress, with one enlargement in the 

 trachea, as figured in the Bcrli?i transactions. It is also 

 related by Mr Simmonds, that two specimens of AT. 

 Merganser, and two of M. Castor, now at Edinburgh, 

 have only eighteen feathers in the tail. Those in my 

 museum differ in this respect ; the former has certainly 

 that number, but the latter has twenty : this specimen 

 I obtained fresh, and being a female, it was destitute 

 of labyrinth. 



It is much to be wished, that this subject may be 

 more minutely investigated by those, who, from situa- 

 tion, may have more frequent opportunity; for, so rare 

 are these birds become, in the southern parts of the 

 kingdom, that, in the course of nearly thirty years col- 

 lecting, I never obtained but the single specimen be- 

 fore mentioned, in a recent state. 



