414 Dr. Kidd oh the Analomi/ 



discernible, some running in the direction of its length, others 

 surrounding it in the opposite direction; and it is lined by a 

 very thin membrane having a cuticular character. 



The tube which passes from the crop towards the intestines 

 commences so near the termination of the oesophagus, that ex- 

 ternally it appears to be a continuation of the latter ; it is very 

 thick and strong in comparison with its diameter, and consists 

 of a coat of muscular fibres disposed circularly, lined by a 

 membrane which has evidently a glandular character. This 

 tube terminates at a short distance from its commejicement in 

 a small organ, scarcely larger than a hemp-seed, which may 

 very properly be called a gizzard ; though more complicated 

 in its structure, and more effectual for the intended purpose 

 than the gizzard of any bird. 



The form of the gizzard is nearly spherical, and it consists 

 of a thick external muscular coat, which is lined by a glandu- 

 lar membrane of very singular construction, the inner surface 

 being divided longitudinally into six equal parts, separated 

 from each other by two horny ridges of a dax'k-brovvn colour : 

 each division is furnished with three series of serrated teeth, 

 of the consistence of tortoise-shell, and nearly of the same co- 

 lour, running from the top to the bottom ; of which those of 

 the middle series are twice as broad and more complicated in 

 form than those of the lateral series. As there are fifteen 

 teeth in each of the three series of the six divisions, the giz- 

 zard contams in the whole 270 teeth *. In separating the 

 muscular coat of the gizzard from that which lines it, (which 

 may be easily done by maceration,) the exterior surface of the 

 glandular coat in which the teeth ai'e inserted is exposed to 

 view. The appearance of this sui-face is very singular, and 

 may be compared to a piece of fine lace-work, of which the 

 meshes represent the intervals of the inserted teeth, the parts 

 of the membrane in which the roots of the teeth are inserted 

 resembling the lace-work itself. 



Four of the divisions above described are elongated so as 

 to terminate in a tapering membranous appendage, consisting 

 of a natural fold, which serves to convey onwards any fluid 

 particles that may have been pressed out by the action of the 

 gizzard ; and these four appendages so collapse together as 

 to form a point as it were, which lies immediately in contact 

 with the commencement of the common intestines. This ap- 

 paratus is only discoverable by dissection ; for it is contained 

 in a large membranous cavity of the shape of a horse-shoe, 

 the base of which passes across the lower extremity of the giz- 



* Vide Plate II. fig. 6. Plate III. figs. 7 and 8. 



zard, 



