portion of the curve, which they follow, ultimately dividing
into two slips, one of which—inserted upon the surface of the
bone of divarication—governs the length of the preceding
flexible portion of the tube ; the other slip passes off downwards
to be attached to the inner surface of the breast-bone,
anterior to the first rib. The course of the muscle on one
side may be traced in the first anatomical figure.
Dissection, which conclusively proved the distinction
between the Wliooper and Bewick’s Swan, has also shown
that the two Wild Swans of North America differ internally
as well as externally from the two Old World species already
described. The largest of the North American Swans,
superior in size to our Whooper, is called Cygnus buccinator,
or the Hunter’s Swan, by Richardson, in his £ Fauna Boreali-
Americana,’ where the measurements and other particulars
of its history will be found. The Author was indebted to
the liberality of Richardson for a preparation of the very
singular organs of voice and the sternum of this species,
which will be found described and figured in the Transactions
of the Linnean Society, vol. xvii. An immature Swan,
which in the opinion of some ornithologists belongs to this
species, is in the Aldeburgh Museum ; being one of four
killed in October 1866 (Hele’s ‘ Notes about Aldeburgh,’
p. 147). However, the sternum of another bird out of this
flock, proved, on examination, to have no cavity for the
windpipe, therein resembling the Mute Swan; whereas the
genuine C. buccinator has a cavity like that in the Whooper !
The second species of North American Swan was described
by Dr. Sharpless (American Jour. Sc. xxii. p. 83), under
the name of Cygnus americanus [C. columbianus, Ord]; and
subsequently by Audubon. The Author was presented by these
gentlemen with the organ of voice and the sternum from
several examples of this species, which in some respects, internally
as well as externally, resembles our Bewick’s Swan,
although attaining a size and weight almost equal to those of
our Whooper; the whole length reaching four feet six inches,
and the weight twenty-one pounds. Macgillivray was under
the impression that he had recognized an example of this
American Swan in an immature bird purchased at a poulterer’s
at Edinburgh in February, 1841, and he described it
as such. Again, five Wild Swans were found in a poulterer's
shop in Edinburgh on the 26th December, 1879 ; and it was
stated that four of these on dissection also proved to be
C. americanus (Zool. 1880, p. 111). There seems, howevei,
good reason to doubt the correctness of the diagnosis, and
some remarks on the subject, with illustrations of the bills
of this and Bewick’s Swan in the £ Proceedings of the Natural
History Society of Glasgow,’ vol. iv. p. 318, maybe consulted
with advantage by those who are in haste to add fresh species
of wraterfowl to the ‘ British ’ list.
The vignette represents a front view of a portion of the
body of Bewick’s Swan; the anterior part of the descending
windpipe being turned aside to show its inner ascending
part, the muscles of voice, and the tendinous fascia stretched
across from one branch of the forked bone or merrythought,
over to the other, by which both portions are supported.
This, and other anatomical representations, necessarily very
much reduced in size here, will be found on a larger scale
in the sixteenth volume of the Linnean Transactions.