Dr. Latham'; EJfay on the Trachea or Windpipes of Birds. 105 



circumftance, we may conclude that other varieties may be occa,- 

 fionally met with. 



Whether the female has fuch a conformation of parts is not 

 in my power to determine; but it may be obferved, that the two 

 birds differed by the Academy of Sciences, as well as my own, 

 were males. 



VIII. ARDEA VIRGO — Demoiselle Heron. Tab. x. Fig. 4. 



A. fuperciliis albis poftice retrorfumque criftatis. 

 Ardea Virgo, Linn. Syft. Nat. i. p. 234. — Ind. Om. 2. p. 673. 

 La Gruc de Numidie, Buf Of. vii. p. 313. p j. i 5 ._p/. £il. 241. 

 Demoifelle or Numidian Crane, Gen. Syn. v. p. 35.— Edw. PL 134. 

 Pltf. Mem. t. p. 204.— Phil. TrStnf. lvi. p. 210. r. xi. f. 5. 



This beautiful and elegant bird is well known in our menageries 

 and is frequently fo tame as to mix with the poultry, though in the 

 winter feafon it requires defence from cold. In it the trachea 

 enters a cavity in the keel of the irernum for about three inches 

 when it returns after making a bend as in the two following fpecies, 

 and paffes into the cheft. I had, many years fince, an opportunity 

 of obferving this circumftance in a fpecimen of my own; but, from 

 the great length of time, the part had fo far periflied as to render it 

 impoflible to take a drawing from it. I am therefore conftrained to 

 copy the figure in the Philofophical Tranfa&ions, which I have 

 not the leaft doubt of being fufficicntly authentic. 



IX. ANAS CYGNUS— Wild Swan. Tab. xii. Fig. 1. 2. 



A. roflro'femicylindrico atro, ceii flava, corpore albo. 



Anas Cygnus, Linn. Syjl. Nat. i. p. 194. — Ind. Om- 2. p. 833. — 



Brlf.Orn. vi. p. 292. t. 28. — RaiiSyn. Av. p. 136. A. 2. 

 Vol. IV. P Cygne 



