20 PRACTICAL ORNITHOLOGY. 



crop, passes over to the right side of the neck, along which it 

 proceeds until it enters the thorax, when it passes to the left 

 side, dilates into the proventriculus, f, and joins the stomach, g, 

 which lies on the left side, and is of a roundish form, being 

 distended with food. The duodenum, h, i, j, commences the 

 intestinal tube, which ends at the anus, k. The left pectoral 

 muscle, /, has been cut through ; the sternum has been thrust 

 aside, the blood-vessels have been removed, and there are seen, 

 the heart, m, the right lobe of the liver, n, the left lobe of the 

 same organ, o, together with part of the lungs, p p. The 

 trachea, or windpipe, q, r, s, extends from the mouth, along the 

 fore part of the neck, inclining to the right side, and again turn- 

 ing toward the left ; at t, over the oesophagus, it divides into 

 the two bronchi, u u, which enter the lungs, pp. A very 

 slender muscle, v v, is seen passing down on each side of the 

 trachea, and at w is a sort of pad composed of several small 

 muscles. This part, it', is the syrinx, or inferior larynx, while 

 at the other end, d, is the larynx, or superior larynx, which, 

 however, is not well seen in this view. But as the parts here 

 are rather small for an unpractised observer, it will be better, 

 in order to understand the structure of the windpipe in detail, 

 to have recourse to a larger bird, the Rook, in which they can 

 be more easily ascertained. 



In Plate XI, Fig. I shows the tongue, hyoid bones, trachea, 

 bronchi, and lungs, of the Rook, Corvus frugilegus, together 

 with the digestive organs, and part of the kidneys. But, to 

 begin at the beginning, let us turn to Fig. 2, which represents 

 the hyoid bone, or the bone of the tongue, which we there see 

 to be composed of several pieces, articulated to each other ; and 

 first of a body, a b c, and two appendages y def, d ef. The 

 body is formed of three bones : a, the glosso-hyal, which in the 

 rook is covered with a horny sheath, represented by a in Fig. 1 ; 

 6, the basi-hyal, or basis of the hyoid bone ; c, the uro-hyal, 

 which here is almost entirely cartilaginous. Each of the appen- 

 dages is formed of the apo-hyal bone, d ; the cerato-hyal, e ; and 

 the terminal cartilage,/". 



Referring now to Fig. 1, we have first the tongue, or rather 

 its horny sheath, a, which covers the glosso-hyal bone ; b, the 



