88 American Wild Swan. 
Another preparation (Plate I, fig. 2.) six inches and one half long, 
of a younger swan than either of the preceding, developed a rising 
on the internal surface of one inch in diameter, with the trachea en- 
tering but four inches and three fourths, and just assuming the horizon- 
tal position—and the very young bird already mentioned, and which 
was no doubt a yearling cygnet, produced a sternum six inches and 
one half in length, with the trachea entering three inches and one half, 
and preserving a vertical fold, and showing merely a gentle swelling 
in the bone at the posterior termination of a cavity four inches deep. 
(Plate I, fig. 3.) In every instance, the trachea, upon approaching 
are separated anterior to it by a strong ligament, which stretches ina 
right line across from one limb of the merry-thought to the other, 
and extends from the outlet from the keel, to near the union of the os 
furcatorium with the clavico-scapular bones. Lateral Jigaments also 
pass from the limbs of the merry-thought to these bones, and form a 
chamber for the pulmonic portion of the trachea to lie in. (Plate II, 
fig. 2.) The muscles of voice pass from one portion of the tube to 
the other, and are united to the sternum as in the English species. 
The bone of divarication is placed perpendicular to the sternum, 
and is one inch and an eighth from top to bottom, and the sides are 
so compressed that they are nearly parallel. The space between 
this bone and the bronchial rings is half an inch, and is occupied 
by a membranous tube, outside of which, extends another membrane 
from the edge of this bone to a delicate semi-circular bone on each 
side, which protects the structure within. (Plate II, fig. 1.) This 
arrangement is nearly the same as in the Bewic 
inneus gives the wild swan as having but decen ribs, and the 
tame, twelve,—while the ‘article Swan in “ Delineations of Zoologi- 
cal Gardens, London,” states the wild to have twelve, and the tame 
swan but eleven ribs. Mr. Ord (than whom there cannot be better 
authority in ornithology,) assisted me in ‘ascertaining the number of 
ribs in the dried specimens I possess, and we were unable to discover 
more than ten, the first of which did not reach the sternum, but was 
united to the second by a membranous connection.—A particular ex- 
amination of these bones was unaccountably neglected whilst the birds 
were recent, and there may possibly be an error in the number o 
ribs. There were twenty six true verte 
The gizzard of the specimen. particularly ¢ diceaibacsd above, weighed 
five and a half ounces—and the intestines were in every case coiled 
