B I R 
B I R 
Bird;, from the rapidity of it's motion, would pro- 
bably ftrike againft almofb every objedt in it's way; 
as well as be totally incapable of difcerning it's 
proper food when foaring in it's own element. 
Thus the kite, though at an aftonifliing height 
from it's prey, darts on it with the moft unerring 
aim ; and the hawk defcries the lark at a dillance 
far beyond the reach of the human eye. 
All Birds are deftitute of external ears, being 
only furnifhed with holes for the purpofe of convey- 
ing found to their auditory dufts. The horned 
owl, indeed, and a few other Birds, feem to have 
•external ears ; but this appearance is occafioned by 
tlie projedlion of fome feathers beyond the reft on 
each fide of their heads. It is probable, how- 
ever, that thofe feathers which encompafs die ear- 
holes of Birds fupply the defeds of their exterior 
ears, fo far as they are inftrumental in tranfmitting 
various founds to their internal fenfories; and the 
extreme delicacy and fenfibility of their organs are 
eafily proved by the facility with which fome Birds 
learn mufical notes, as well as by the great exadt- 
nefs of their pronunciation of words. 
The olfaftory nerves in the generality of Birds 
appear equally curious: fome of the feathered tribes 
fcent their prey at a vaft diftance; and others, 
by the fenfe of fmelling, avoid their infidious pur- 
fuers. In decoys for catching ducks, thofe who 
attend on that bufinefs always keep pieces of turf 
burning near their mouths, on which they con- 
ftantly breathe, left the fowls Ihould fmell them, 
and confequently avoid their lures. The univer- 
fality of this pradlice puts the propriety of it be- 
yond a doubt ; and proves the extreme delicacy in 
the olfadory fenfation with which this fpecies at 
leaft of the v/ingcd creation is endowed. 
The legs and feet of Birds are lighdy conftru6l- 
ed, for their eafter tranlportation through the air. 
The toes of thofe which are calculated for fwim- 
ming in the v/ater are webbed ; but, in other Birds, 
they are disjoined, the better to enable them to re- 
tain objefts, or cling to the branches of trees with 
fecurity. Such Birds as are furniflied with long 
legs have alfo long necks, as they would otherwiie 
be incapable of picking up their food : fwans and 
geefe, however, whofe necks are extremely long, 
have very Ihort legs ; and are for that reafon bet- 
ter adapted for Iwimming than walking. Thus 
every external part appears fitted to the life and 
fituation of the animal. Nor are the inward parts, 
though not immediately appropriated to flight, 
lefs neceffaiy to fafety : the bones of every part of 
the body are extremely thin and light, and all the 
mufcles very flight and feeble, except thofe whicli 
afford motion to the wings ; while the tail ferves 
to counterbalance the head and neck, to guide the 
animal's flight like a rudder, and to affift it in it's 
afcent and defcent. 
If we minutely examine the internal parts of 
Birds, we fliall find the fame wonderful confor- 
mation fitting them for living in air, and increaf- 
ing the furface by dimjnifhing the folidity. Their 
lungs adhere to the fides of their ribs and backs ; 
i>ViX. the extremities of the branches of their wind- 
pipes open into them ; while tliefe have a com- 
munication with the cavities of their bellies, and 
convey the air drav/n in by breathing into cer- 
tain receptacles refembling bladders, extending 
the whole length of their bodies. Nor are thefe 
opening? obfcure, and difficult to be dii'cerned ; 
for a probe thruft into the lungs of a fowl will 
eafily find a palTi\ge into the belly] and air 
blown into the wind-pipe will be feen to diilrend 
the animal's body. In quadrupeds, this pafl^age 
is intercepted by the midriff; but, in fowls, the 
communication is obvious, and confequently they 
with much greater facility take long and large in- 
fpiration. Sometimes alfo the wind-pipe makes 
many convolutions within the body of the Bird, 
and it is then called the labyrinth ; but of what ufe 
thefe turnings or windings are to particular Birds, 
neither naturalifts nor anatomifts have hitherto been 
able to develope. This diff'erence of the wind- 
pipe is often found in Birds that, to all appearance 
at leaft, are of the fame fpecies: thus, in the 
tame fwan, the wind-pipe makes but a ftraight 
paflfage into the lungs; v/hile, in the wild fwan, 
it pierces through the breaft-bone, and has feveral 
turnings before it comes out again and proceeds to 
enter the lungs. Thefe convolutions, however, are 
not inftrumental in forming the voice of the Bird; 
fince thofe fowls which are deftitute of them are 
neverthelefs vocal. We cannot therefore aicertain 
from whence ibme Birds derive the loud and va- 
rious modulations in their warblings : but we may 
venture to aflJert, that fowls, in proportion to their 
bulk, have louder voices than animals of any other 
kind; for the fcreaming of a peacock is as loud as 
the bellowing of an ox. 
Though all Birds, properly fpeaking, have but 
one ftomach, it is, however, very unlike in diffe- 
rent kinds. In all the rapacious tribes the ftomach 
is peculiarly formed : the oefophagus, or gullet, 
in them, is found to be replete with glandulous 
bodies, which ferve to dilate and macerate their 
food as it paflxfs into their ftomachs, which are al- 
ways very large in proportion to the fizes of the 
Birds, and are generally enveloped in fat, in order 
to increafe their warmth, and afllft their digeftive 
powers. The inteftines of frugivorous Birds are 
difi^erently formed from thofe of the rapacious 
kinds: the gullet, in them, dilates juft above the 
breaft-bone, and forms itfelf into a pouch or bag, 
called the crop, which is replete with falivary glands, 
ferving to foften and moiften the food which it 
contains; and thefe glands are furnifhed with longi- 
tudinal openings, which emit a whitifh and vifcoua 
fubftance. The dry food of the Birds, after being 
macerated for a convenient time, paflTes into their 
bellies; where, inftead of a fofr, moift fluid, as 
in the rapacious kinds, it is macerated betv/een 
two pairs of mufcles, commonly called the gizzard, 
internally covered with ftony ridgy coats, and al- 
moft cartilaginous: thefe coats, rubbing againft 
each other, are capable of bruifing and attenuating 
the hardeft fubftances, their a£lion being fimilar to 
that of the grinding-teethin man and other animals. 
Thus the organs of digeftion in Birds are in aman- 
ner reverfed. Beafts grind their food with their 
teeth ; after which it pafl^es into their ftomachs, where 
it is foftened and digefted: on the contraiy. Birds 
firft macerate and foften it in their crops, and then 
it is o;round or comminuted in their ftomachs or 
gizzards. Birds are alio careful to pick up fand, 
gravel, and other hard fubftances; not to grind 
their food, as has been fuppofed, but to prevent 
the too violent aftion of the coats of the ilomach 
againft each other. 
Many' fpecies of Birds are provided with two 
appendi'ces, or blind guts, which in quadrupeds 
are always found fingle. Among fuch Birds as 
are thus fupplied, are all carnivorous fowls : and 
all Birds of the fparrow kind have very fmall and 
fhort ones j while water-fowl, and Birds of the 
1 A poultry 
