1880. | Sandhill and Whooping Cranes, 113 
there are two—an anterior and a posterior—large empty air cells 
in the bone, with smooth walls, and two other air cells—one 
superior and one along the edge of the keel—filled with light 
bony meshwork. * * * The trachea, entering the apex of 
the keel, traverses the whole contour of the keel in a long verti- 
cal coil, emerges at the front upper corner of the keel, enters 
again at the lower corner of the keel, and makes a smaller 
vertical coil in the center, emerging again where it went in. On 
looking at the object from the front, we see three parallel verti- 
cal coils side by side; the middle one is the trachea coming 
down from the neck above; on the left hand is the bulge of the 
first great coil; on the right is the windpipe passing to the lungs 
after it has made its second coil inside.”! Following this is a 
statement to the effect that “there are about twenty-eight inches 
of windpipe coiled away in the breast-bone,” and that altogether, 
from the upper larynx to the bronchi, the trachea is fifty-eight 
inches in length, and this in a bird that is little over four feet long 
from the tip of the bill to the end of the tail. 
_ The average of three specimens shows the entire length of the 
trachea in canadensis to be about twenty-seven inches. 
Audubon, who regarded G. canadensis as the young of G. 
americana, has, curiously enough, left us a description of the 
tracheal apparatus of the former but not of the latter. His 
description is taken from the sternum of a crane which he kept 
for a season in confinement, and which the reader would be led 
to infer turned white while in Audubon’s possession, though this 
change of plumage is not directly stated to have occurred. I 
quote the brief description which, it will be readily seen, applies 
to canadensis and not to americana: “ The trachea, which is 
thirteen inches long to its entrance between the crura of the 
furculum, passes into a cavity in the sternum where it curves 
So as to describe two-thirds of a circle, returns on the right _ 
side and enters the thorax by curving backwards. The cavity — 
of the sternum is two inches long, with an equal depth, and T 
a breadth of three- -quarters of an inch. The ridge of the - 
keel is, at its fore part, three-quarters in breadth, and contracts _ 
to one-half inch at its junction with the angle of the furcula, es 
which is continuous with it. * * * * Boston specimen.” — 
It is Strange that Audubon, who appears to have been a close 
! Besides at page 530 of “ Birds of the North- aTi this a dail = also b 
found in full in Forest ser Stream for Phin 20, oei 
