502 Mr. Brookes oji the Formation of the Trachea 



nary structure of the trachea : quans, curassows, the caperkallj^, 

 and riionygama Keraudrenii, are instances of those exceptions. 



Nothing striking in this respect occurs in individuals of the 

 order Rapt ores, all of which have an ingluvies, with an osfurci- 

 forme very strong, and bent concavely for its support ; whereas 

 in the Rasores the same bone is of so delicate a nature, that in 

 one of the largest species, the turkey, it is even of a slighter 

 texture, in proportion to the size of the bird, than in all the 

 other genera. This circumstance arises probably from the spe- 

 cies of this order being constructed more for walking than 

 flying ; the turkey especially, whose migrations are sometimes 

 of considerable extent, performing them chiefly on foot. The 

 Strut hionidcB have no perfect osfurciforme. 



I hope to be understood as not implying that there is no 

 peculiarity of the larynges and tracheae, except in some genera; 

 for I believe all have the admirable mechanism of the organ of 

 voice differently constructed, with corresponding muscles, and 

 distribution of nerves, producing those various modulations of 

 sound so familiar to us, and destined for the excitement of love, 

 as well as for other purposes. 



It would seem superfluous in me to offer further observations 

 on this head, after the luminous representations which are to be 

 found in different authors, demonstrating these facts, but more 

 particularly by Mr.Yarrell, who favoured the Society with highly 

 interesting details of this curious subject, illustrated by prepa- 

 rations, and drawings of the remarkable forms of the labyrinths, 

 larynges, divaricating septa, and extensive contortions of the 

 tracheae in various species, as well as of the appropriate muscles, 

 some of which were before altogether undescribed. 



It may be thought worthy of remark, that the Tantalus affords 

 the only instance, I am acquainted with, except the spoonbill, 



of 



