OCR Text |
Show 1879.] TRACHEA OF THE GALLING. 375 of the rings alone. In the adult male the four lowest rings blend in the middle line, both anteriorly and posteriorly. Those higher up do not do so. The last ring of the trachea, the whole plane of which is transverse, sends downwards a bluntly triangular medio-anterior process, with the lower margin of which the first bronchial semirings articulate. Posteriorly, in the full-grown bird, the pessulus fuses with the hinder extremities of the same, in such a way as to m a k e it appear to form a continuation of it, as in no other of the Gallinae with which I a m acquainted. The first bronchial semiring sends upwards at right angles a strong anterior articular process, it posteriorly expanding triangularly, so that the upper angle meets the lower margin of the last tracheal ring in the usual Fig. 28. Fig. 29. Front view. Back view. Numida cristata. situation, the lower angle articulating with the second semiring, whose other end bends up to be jointed to the corresponding part of the first semiring, developed slightly downwards to articulate with it. The interval between the last tracheal ring and the first bronchial semiring is considerable and broadly quadrilateral; that below it is m u c h shallower ; and those above are fusiform, diminishing gradually as they ascend, until the last is quite minute. N. ptilorhyncha and N. rendalli are very similar. They agree with one another, and differ from N. cristata in that the extreme lateral edges of the penultimate and last tracheal rings meet and blend, thereby reducing the interannular interval to a guttate form, |