Warblers, Larks;. Buntings* Finches,*' Swallows,Sec.; the
organs of voice in which vary only m size, In 'birds ^possessing
powers of song, or imitation, the tube-of the trachea is
nearly uniform in. shape throughout, the bronchi® long5' in
proportion; and both parts perfectly flexible'.-;.: The - fourth
group here introduced exhibits, fig, l r a front view—fig. 2, a
S I B 2 E
* The Canary is a true Finch, possessing, likfe the best Sang Birds, fiv?
pair qf true m u s c le s v o ic e , and,,hence arises its, power/of .imitatTng^ether
sounds, as evinced in the Cainary which has fot some time past formfed ari inter-
esti'ng.subject of exhibition in London,.
back viewi—and fig. 3, a side view—»of. the lower portion of the
trachea ahd its muscles in the Raven, which may be consi-
dere'd-the 'type of this form, and from its size admits of clear'
explanation.. F ig u r e ^ and-3,offthe second group, page 72, /
exhibit an outside and an inside view of - the same part, but
divested, of its muscles,- t;0 §how by the prevalence and interposition'
of /-membrane,• the degree of alteration the various
muscles' are-able .to effect.'
' ' Referring''again'to the fourth group, .On the opposite page,;
thd pair of mtfscles which descend ou t|ie outside of the trachea,,
divided ait a^ho^t.-dis,tancé above the end* of the tube, and one
“portfon-is directe® iuI*contifiu!a%ion c|ówn wards and "backwards,
tdfb'e inserted, upbnvthe extréme posterior end of «the first bone
of th e bro,nehia„ audr is marked*ƒ. Its counterpart passes from
tjfe- place àf'séparàtion downwards and forwards to be inserted*
below theV^tfeinetpl^nt? of éhedast bone o f the tube, and- is
marked Within the angle ' formed by the "separation of
th es,öA'tw'e^ïiiCs'e^^a third slender and c’erd-likdunuscle arises/
which be- inserted-4,upon thé -sternum,- as in those1
ffirds-Mjang on’e.pair ; thn^b" âreym'arked (L The ( fourth
; ni'Usfel^ marked A, is-the shortest of the five*', * I t arises near
, thlghentre, of 'the^botfom of the tube, and its fibres, directed
•-^liquefy backwards and downwards, are inserted by tendon
UpoMthe^extrenaity of the first half-circular bone, ,, ’ The fifth
mus'êfe, marked g,Arises also from the centre of the tube,
similar to the1:,last, but is something ionien and thicker,
having-®© appearânee^èf being made upa ofoeveral small mus-
cliflin .^^^obntàçfü Its -Wfeciion is, obliquely downwards
-and forwards,'-Æ^^.-festance in pkrt hid by the muscle-marked
e,-ând it’ is attacfied^Dy~E~ broad base to tbe last bony ring of
tlStube, to1-the cartilaginous projection’immediately below,
and sends tOspè portion-to be inserted- upon the extreme end
of the.first bronchial bWe^Figure 4 represents these five
muscles, three of- them being partly detached to render them