Page 355. 
478 ON THE TRACHEA OF THE GALLINZE. 
It is in the Peafow] that the thoracic terminations of the trachea is 
less complicated, as far as my experience goes, than in any other 
Gallinaceous bird ; and the arrangement isso simple that it is not — 
to imagine one mins more so.* 
In the chick (a month old) of Pavo spicifer (figs. 1, 2) the ante- 
penultimate tracheal ring is free, and agrees with those above it in that 
the interannular intervals are reduced to a minimum, at the same time 
that anteriorly it is slightly bent downwards in the middle line, to 
assist in the changes of form connected with the bifurcation of the 
tube. The penultimate ring, from its position, is more pronounced 
in this respect, whilst posteriorly the pessulus runs up to blend with 
it, not at its inferior margin, but by a wedge-shaped cartilaginous 
expansion, the apex of which touches the lower margin of the ring 
above. That this is so is proved by the existence of two oblique 
indented lines, one on each side, converging superiorly, where they 
nearly meet to form the apex of the just-mentioned wedge. The last 
tracheal ring anteriorly sends down an obtuse median process, the 
inferior margin of which constitutes the summit of the notch between 
Fig. 1. Fig. 2. 
p= By 
anne 
S 8 
Front view. Back view. 
Pawo spicifer (adult). 
N.B.—This and all the subsequent diagrams are drawn to one scale; and have 
no relation to the actual size of the structures. 
the divaricating bronchi, whilst its posterior surface forms the anterior 
attachment of the pessulus. Posteriorly this ring is incomplete, the 
two obliquely truncated ends being separated by a considerable interval 
occupied by the pessulus in the middle line, and laterally by the com- 
mencement of the membranous inner walls of the bronchi. 
* Vide Temminck, loc, cit. pl. i. fig. 2. 
— se 
