OCR Text |
Show 532 MR. A. H. GARROD ON THE [Julie 3, thirteen and the right ten complete rings above the commencement of the syrinx. Each semisyrinx, as it may be termed, is formed on the same principle as that of the combined organ in most of the non-singing birds. Taking for description that of the left side in the specimen figured, it is there found that the thirteenth Fig. 3. Front view of the syrinx of Steatornis. bronchial ring is complete, though considerably flattened from side to side ; the fourteenth is not complete in the middle of its inner surface, it is a little longer from before backwards than the one above, and not so long as the one following it. The fifteenth is only a half ring, its inner portion being deficient; it is slightly convex upwards, and articulates, both at its anterior and posterior ends, with the fourteenth incomplete ring and the sixteenth half ring. The sixteenth half ring is concave upwards, and so forms an oval figure in combination with the one above, which is filled with a thin membrane, to form part of the outer wall of the bronchus. There is a membrane also between the ends of these and the succeeding half rings, which completes the tube of the bronchus internally. The half rings which follow the sixteenth reduce in size, and are considerably smaller before they reach the lung. The lateral muscle of the trachea extends down the outer side of each bronchus, to be |