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are as highly prized from furnifliing occupation to the 

 fportfman, or a delicacy to tlie epicure. 



The anatomical cliaraclers of this clafs of animals, are not 

 lefs defcrving of attention than their ot'ier properties. In the 

 fcale of animated exiilence, birds can Icarccly be confidercd 

 inferior to mammalia ; and yet many of their functions are 

 exercifed upon a veiy diffmiilar plan, and alrnofl conihmtly 

 by organs differently conlbitutcd. it is in birds that we 

 perceive the firft general deviations from the fchome of orga- 

 nization purfued m the human fubjeft : this will be found 

 mod remarkably exemplified in the apparatu'i for the prepa- 

 ration and digellion of food, the fecretio;i of urine, the mode 

 of generation, and the growth and economy of the young 

 animal, the anatomy of the brain, the llru£ture of the eye 

 and ear, the mechanifm of the organs of found, and the cor.- 

 ftruftion of the inftruments of loco-motion. 



The anatomy of birds has been much profecuted both by 

 the older authors and in modern times, as the means of phy- 

 fiological knowledge, and in aid of the fcveral purpofes for 

 which thefe animals arc fo much eftimated. The information, 

 however, communicated in this way, falls far (hort of a fyf- 

 tematic account of the fubjeft ; to fupply which, therefore, 

 much original matter is nccefTarily introduced into the pre- 

 fent article, more particularly in the delcriptions of the blood- 

 veffels, of the organs of motion, and of the minute ftruc- 

 turc and ufes of parts. Many errors of the older writers arc 

 alfo correfted ; and wherever the defcriptions of others are 

 followed, they have been, as far as it has been prafticable, re- 

 vifed by a comparifon with the recent fubjeft or authentic 

 preparations. 

 Organs concerned in the Exercise of the vital 

 Functions. 

 The Aluulh and its coiilained Paris. 



In the other clafles of animals, th<rfe parts are con- 

 ilrufted to effeft the divifion of the food previous to its 

 paifage into the ftomach, but in birds the procefs of maf- 

 tication is either imperfeftly performed, or carried on 

 by a peculiar mechanifm to be afterwards defcribed. 

 Birds are unprovided with thofe foft and flexible parts 

 called lips ; tlie aperture of their mouth is made by the 

 prolongation of the two jaws, which are covered with a 

 hard and horny fubilance. Thefe are named the upper and 

 the lower mandlUes, and together form the leak or hill. 

 The bones which enter into the compofition of the bill, will 

 be confidered along v.ith the other parts of the fteleton. 

 The external or horny part is produced, like other fnnilar fnb- 

 ilances, from a vafcuiar and fpongy membrane, which is in- 

 terpofed between it and the bones ; it correfponds exactly 

 in (hape with the jaws, which ferve it as a mou'd. 



The bill is dehgned for many different purpofes, and'con- 

 fequently is fubje£l to great variety in its conformation. In 

 the birds of prey it is Itrong, hooked, fliarp, and furniihed 

 with a tooth-hkc procefs on its edge, to enable them the 

 better to feize and lacerate their prey ; thofe birds which 

 fubfilt on fmail grain, are provided with (hort, pointed, 

 fharp.edged bills for picking up and breaking their food ; 

 the parrots alfo ufe their bills for dividing their meat ; in 

 thofe inflances, therefore, the bill may be confidercd analo- 

 gous to the teeth of other animals ; but it is only the inci- 

 fors with which it can be compared, as it is incapable both 

 from its thin edges, and from the nature of the articulation 

 of the lower jaw, of performing any thing like the grinding 

 motion in which properly mallication confifts. 



The pifcivofous birds have commonly large and extended 

 bills, which become necefiary to them, in order to fecure 

 their prey ; thefe birds almoft always fwallow their food 

 without dividing it. 



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Swallows zn& goat-fuclers have fliort bills, but opening 

 very wide, fuitablc to their mode of procuring their food, 

 which confitls in taking flies while the bird is on the wing. 



The ii'ciod-pcckers, ivry-necks, nul-katches, &c. life the bill 

 as an inltrument for peiforating the bark of trees, and break- 

 ing nuts ; for which purpofe it is conftru6ted like a wedge. 



It may, in fine, be given as a general obfervation, that 

 the form and llruclure of the bill indicate the proper habiti 

 and economy of the birds ; they have therefore been al- 

 ways employed by naturalills as claffific dillinftions, and to 

 their works we refer the reader for a more detailed account 

 of the peculiarities obfcrved in the bills of birds. 



In confequence of a particular mechanifm, arifing from 

 two additional bones, the upper jaw of birds is capable of 

 a certain degree of motion. In general this is very confaicd, 

 but the piu-rot tribe are able to move the upper jaw with 

 confiderable freedom. The bones and mufcles upon v. liich 

 this peculiarity depends, will be defcribed with the organs 

 of motion. 



The cavity of the mouth is lined with a thick vafcuiar mem.- 

 biane, behind which are placed a great number of follicular 

 glands, which difcharge a mucous liquor upon tveiy part of 

 the furface of the mouth. They are, however, moll abun- 

 dant in thofe parts which fuftain moll friction, as the com- 

 mencement of the cefophagus, and furrounding the aperture 

 of the nares, in the upper and back part of the mouth. 



A cuticular tunic is fpread over the glandular membrane, 

 which is as ufual fo foft and dehcate, that it cannot without 

 difficulty be detefled. 



The tongue of birds can hardly be confidered an inftru- 

 ment of manducation ; its motions are very limited, in con- 

 fequence of its containing a bone which runs through its 

 whole length, and the lingual bone being articulated behind 

 with the OS hyoides, which determines the extent of its move- 

 ments. The only biids, in which the tongue is immediately 

 concerned in the divifion of the food, are \.ho{e pajferes livinf 

 upon feeds that are inclofed by a (hell. In fach the tongue 

 is employed to convey the feed between the edges of the 

 bill, and fecure it there until it is broken, which is not un- 

 like theaftion of the tongue of mammalia during mailication. 



The tongue of the ivooil-pccters and -wry-necks is an organ 

 of curious llrufture, and enables thefe birds to transfix their 

 prey at fome dillance from the mouth ; the mechanifm by 

 which this is accomplilhed, and the bones and mufcles whicli 

 belong to the tongue in general, will be particularly defcribed, 

 with the other organs of motion. The varieties in external 

 form, and the llruCl:ure and integuments of the fubftance of 

 the tongue, will be confidered under the head of the organ 

 of talle. 



Salivary glands have been afcribed by moft authors to 

 birds ; but as it would appear, without duly confidering the 

 ufes of thefe parts. Birds, as already obferved, do not com- 

 minute their food by mallication in the mouth, for which 

 purpofe the faliva is employed by other animals ; and the 

 glandular bodies, which have been defcribed as falivary, ap- 

 pear to yield a fluid of rather a mucous than an aqueous na- 

 ture. The internal furface of the mouth of birds i^ bc- 

 fmeared with mucus, in order to facilitate the paflage of the 

 food, which would not be neceflary, if the aliments were 

 foftened by faliva. 



The reputed falivary glands of birds are fituated within 

 the angle formed by the anterior part of the lower jaw, and 

 between the ikin and the inner membrane of the mouth. 

 They are two in number, and appear to be compofed of 

 granular maffes, or follicles, clofcly connected to each other. 

 They difcharge their fecretion into the lower part of the 

 mouth, by means of fome foramina arranged on each fide of 



the 



