VOL. XV.] PHILOSOPHICAL TRANSACTIONS. 175 



though unknown by that name : I was very much pleased to be so suddenly rid 

 of my long continued scruples about it, and not a little surprised when I found 

 it to be another kind of bird than I imagined. A particular description of the 

 cock, you may find in Mr. Willughby's Ornithology, page 366, of the English 

 edition, among the sea-ducks, to which kind this bird belongs, and not to the 

 divers or duckers, (Mergi or Colymbi,) as I falsely fancied to myself. The first 

 knowledge of this bird we had from Mr. Jessop, who sent us the skins of this 

 among others stuffed, from Sheffield in Yorkshire, by the name of Scoter, as it 

 seems they call it thereabouts. Afterwards the cock of this kind was found in 

 the market at Chester, by the then Bishop Wilkins's steward, who bought it; 

 and brought it home to the palace, where I then happened to be, and saw and 

 described it. •Xastly, Sir Thomas Brown of Norwich sent, among many others, 

 the picture of this duck ; and Mr. Johnson of Brignal, near Greta-Bridge in 

 Yorkshire, the description as I have related in the book, and page before quoted. 



I observed in this bird, and in some others of the sea-ducks that are much 

 under water, that they want that vessel, or ampulla, situate in the very angle of 

 the divarication of the wind-pipe, which for want of a better and fitter name, 

 we are wont to call the labyrinth of the trachea ; which, though being com- 

 mon also to the colymbi, which of all birds dive most and continue longest 

 under water, we may very probably from thence conclude, that the labyrinth 

 does not serve them for a reservatory of air, to enable them to continue the 

 longer under water, as I sometimes conjectured; but for the intending and 

 modulating- of the voice, seeing in the plash-duck the females want it : but I 

 am somewhat td seek about the use of this vessel, and I think it were worth 

 while to examine what sorts of birds have it, and what want it ; whether the 

 males only, or in some the females also. I observed it in the mergus cirratus 

 longiroster major or the dun-diver, and that very large, and extended by very 

 strong bones, and yet I thought myself to have sufficient reason to judge that 

 bird to be the female of the merganser : but I dare not be confident that it is a 

 female, because of this labyrinth. 



And now because I am writing of birds, I propose it to your consideration, 

 whether that sort of bird mentioned by the learned Dr. Plott to be often heard 

 in Woodstock Park, and from the noise it commonly makes called the wood- 

 cracker,* be not the lesser sort of picus martius varius ; for since the publish- 

 ing of Mr. Willughby's Ornithology, I have observed that bird sitting on the 

 top of an oaken tree, making with her bill such a cracking or snapping noise, 



• It is generally supposed to be the nuthatch or titta europaa. Linn, which feeds in a similar 

 manner with the woodpeckers. 



