RESPIRATORY ORGANS. ]59 



In the Falconine Birds, or Eagles and Hawks of all kinds, 

 the last entire ring of the trachea. Fig. 3, is furnished with a 

 septum ; the lateral muscles, ij, which are generally strong, 

 terminate in two slips, one, j k, forming the sterno-trachealis, 

 the other, jf, passing to the last tracheal ring, or the mem- 

 brane intervening between it and the first bronchial ring. The 

 bronchi are furnished with slender half-rings in their whole 

 length, (/ h. The upper larynx. Fig. 8, has on each side of 

 the aperture of the glottis, an external muscle, a, the apertor, 

 and a smaller inferior muscle, 6, the constrictor. In this re- 

 spect it does not differ from that of the Vultures and Owls. 



In the latter birds, the trachea is very short and wide, with 

 remarkably slender, cartilaginous rings, Fig. 9. The lateral 

 muscles, ij^ which are rather slender, divide, as in the Hawks, 

 into two, the sterno-tracheal, jh, and inferior laryngeal, jf. 

 The last entire ring has a septum, and the bronchi are very 

 short and wide, with slender half-rings in their whole length. 



It seems difficult to conjecture why the Vultures should be, 

 properly speaking, destitute of inferior larynx. What is there 

 in their voice or respiration that renders an inferior laryngeal 

 muscle, or a division of the last tracheal ring, inexpedient ? 

 Such questions tend to shew that much remains to be studied 

 in the anatomy and physiology of birds. 



Observations like these may appear unnecessary to the per- 

 sons who view birds merely as composed of skin and feathers ; 

 but to them I now cease from addressing myself. They will 

 gradually disappear from the earth, and their place will be 

 occupied by men who will study birds as organic beings. The 

 attempt which I have made to establish a rational method of 

 study in this most interesting department of science, however 

 feeble it may be, will yet form, I am well persuaded, the com- 

 mencement of a new era among my countrymen, whom I hope 

 yet to see perfecting my favourite study to such a degree as to 

 render these volumes antiquated and eftete. For my own part, 

 I am well pleased to think that my labours, however little ap- 

 preciated by such of my contemporaries as evidently conceive 

 themselves to be the sole depositaries of ornithological know- 



