1875. TRACHEA IN STORKS AND SPOONBILLS,. 299 
windpipe as long as it is in the neck, leave it together as it enters the 
chest to run to their insertions behind the sternal articular ends of 
the second complete ribs, the left one crossing in front of the upper 
of the two loops described below. There are no special lateral 
muscles running to the syrinx. 
The trachea, modified in the manner above described, continues 
its normal course downwards as far as a horizontal plane cutting the 
base of the heart, when it makes a fairly gradual turn through half a 
circle, directly forward, to consequeutly ascend with the posterior 
keel above mentioned, running along the middle of its convex sur- 
face. On reaching the level of the symphysis furculze it makes a 
second semicircular turn to the right, to again descend nearly as far 
as on the former occasion, and making a third similar turn to the left 
whilst in the fold of the first loop, ascends a third time as high as 
the line joining the two sides of the furcula—in other words, to the 
very top of the thoracic cavity. Here it turns backwards to descend 
again, in contact with the first part of the intrathoracic tube, to its 
right side, as far as the level of the apex of the heart and the com- 
mencement of the proventriculus ; where, making a short very abrupt 
turn forwards, it bifurcates into the two bronchi, which therefore, 
uniquely, run from their origins upwards and outwards to their re- 
spective lungs. In this third and last descending portion of the 
windpipe, which has a length of 53 inches, the lower 3 inches are 
considerably flattened in what would be the lateral direction, which, 
through the convolutions it has been called upon to make, is twisted, 
so that the flattening appears to be nearly antero-posterior, the 
median ridge, developed posteriorly, being placed considerably on the 
right side. 
About an inch above this flexure, in which the bronchi bifurcate, 
the previously deep double rings suddenly cease to be developed as 
such, and return to their normal condition just before the peculiarly 
situated and simple syrinx is reached. 
There are altogether 82 of the ossified double rings in the modified 
_ portion of the windpipe. 
The earlier bronchial rings are peculiar in being deep, the fibro- 
cartilaginous rings being ossified and thickened above and below for 
a certain portion (the external) of their circumference. 
Platalea ajaja.—The peculiar convolution, within the thorax, of 
the trachea in Platalea leucorodia is well figured by Mr. Yarrell *. 
The arrangement in Platalea ajaja is, however, quite different. A 
pair of these birds was purchased by the Society on the 13th of 
August, 1870. The female dying on the 27th of July, and the male 
on the 13th of October, 1873, have given me the opportunity of ex- 
amining the windpipe in both sexes. The trachea is simple, straight, 
of uniform calibre, and peculiarly short, extending only two thirds 
down the length of the neck, where the uncomplicated syrinx is 
situated and the bifurcation of the bronchi occurs. The usual pair 
of muscles, one on each side, runs to this syrinx from above, and 
ceases there. The bronchi are fusiformly dilated at their commence- 
* British Birds, vol. ii. p. 504. 
