gG Dr. Latham^ EJfay on the Trachea or Windpipes of Birds. 



fmg, the mufcles of the Ivrynx are flouted in the male, and in the 

 Nightingale are flronger in proportion than in any bird of the fame fize*. 

 We have been imperceptibly led into the above difcuffion, although 

 not originally meant to form any part of our plan, intending merely 

 to illu/trate fuch variations of trachea as palpably differed from the 

 ufual mode, either in refpecl to pofition or ftructure. 



The deviations in refpecl to the windpipe from what is generally 

 ieen, may be divided into two kinds, — The JirJ, wherein this organ, 

 although of equal diameter or nearly fo, differs in being fomewhat 

 longer than the neck, and thereby allowing of a double about the 

 middle of it, as in the JVood Grous — or, being further elongated,, 

 forming one or more folds either within the keel-like procefs of the 

 fternum, which is hollowed out for that purpofe, as may be feen in 

 the Wild Swan r De?noife/le y Crane, &c.-*-or, inftead of entering the keel* 

 runs more or lefs over the furface of the bread beneath the {kin, as 

 inftanced in the Mar at I, Barraka, Guan, and others, as will be here- 

 after noticed. 



The fecond deviation is where the windpipe is unequal in diameter* 

 although not elongated, but alters in lbtape and fize, and in fome 

 birds very confiderably, in its progrefs to the lungs, more efpecially 

 juft before its divarication into the two bronchia, or lung-pipes. 



This laft circumftance has been met with hitherto only in the 

 Duckf and Merganfer genera, or at lead it is in thefe only 

 that the labyrinth I, as it has been termed by authors, has been 



* Mr. Barrington fuppofcs that the Nightingale may be dlftinftly heard at more than 

 half a mile, if the evening be calm. Phil. Tranf. vol. lxiii. p. 279. 



f I will not take upon me to fay that other, and perhaps various kinds of, conforma- 

 tions of the trachea in the Duck genus may not hereafter be noticed; as we have good 

 authority in refpeft to one fpecies, where the windpipe runs on the furface of the breafl 

 in the manner of the Guan. See No. vi. 



% Ampulla feu Labyrinthus, Rail Bjn. Av. p. 135. Will. Orn. p. 253, et alibi. Laby- 

 rinth, #7//. Om. (Ed. Angl.) P . 335, Rafs Letters^. 163. 



4 found ; 



