TRACHEOPHONES—TREE-CREEPER 985 
looping being preclavicular in the former and postelavicular in the 
latter. In both sexes of Cygnus buccinator, C. musicus, C. americanus 
and C. bewicki the Trachea runs ventrally beneath the symphysis of 
the furcula, which bends dorsally to permit its passage, to enter 
the swollen keel, which in old birds it penetrates to the furthest 
extremity,' and thence returns, still keeping below the fureula, on 
its way to the thorax. In all the other Swans the Trachea is 
simple. Among the Cranes almost every degree of development 
may be found, from Balearica where there are no convolutions at 
all, to Anthropoides where the keel is hollowed into a cavity open at 
the sides, to Grus americana and G. communis where it is penetrated 
to its utmost extremity by the Trachea; but no part of the Trachea 
passes ventrally over the furcula. Such a postclavicular loop exists 
in Platalea leucorodia, but not in P. uwjaja, and in the male of Tantalus 
iis, but not that of 7. loculator. For the thoracic, voice-producing 
end of the Trachea see SYRINX (p. 937). 
TRACHEOPHONES (by some written Tracheophonx or Tracheo- 
phont) Johannes Miiller’s name (Abhandl. k. Akad. Berlin, Phys. Kl. 
1847, p. 367) for the second of his three groups of PASSERINI, 
having the trachea furnished with but one or two pairs of vocal 
muscles, and those lateral (cf. SYRINX, p. 940). 
TREE-CREEPER, one of the smallest of British birds, and, 
regard being had to its requirements, one very generally distributed. 
It is the Certhia familiaris of ornithology, and 
remarkable for the stiffened shafts of its long 
and pointed tail-feathers, aided by which, and 
by its comparatively large feet, it climbs 
nimbly in a succession of jerks the trunks or 
branches of trees, invariably proceeding up- Tren-Crerrmr. (After 
wards or outwards and generally in a spiral meee’ 
direction, as it seeks the small insects that are hidden in the 
bark and form its chief food. When, in the course of its search, 
it nears the end of a branch or the top of a trunk, it flits to 
another, always alighting lower down than the place it has left, 
and so continues its work. 
_ Inconspicuous in colour, for its upper plumage is mostly of 
various shades of brown mottled with white, buff and tawny, and 
beneath it is a silvery white, the Tree-Creeper is far more common 
than the incurious suppose; but, attention once drawn to it, it can 
be frequently seen and at times heard, for though a shy singer 
its song is loud and sweet. The nest is neat, generally placed in 
a chink formed by a half-detached piece of bark, which secures it 
1 In C. buccinator and C. musicus the return loop is vertical ; in C. bewicki 
and apparently C. americanus it is horizontal. 
