OCR Text |
Show 1881.] TRACHEA IN THE " RATITE " BIRDS. 785 In Bhea americana (figs. 7, 8) the average diameter of the trachea interiorly is about 1 inch, and it is somewhat compressed from before backwards. The cartilaginous tracheal rings are complete behind. Fig. 7. Bifurcating trachea of Bhea americana, from before. The same, from behind. About the natural size. The intrinsic muscle has been removed on the right side. In fig. 8 the fibrous band running down the middle of the trachea posteriorly, as described above in Casuarius, is also represented. and closely approximated to each other. The last four tracheal rings are soldered together to form a cartilaginous box, the constituents of which are marked out by the interannular sutures, which are only interrupted in the middle line anteriorly and posteriorly. |