B I R 



B I I^ 



JentTtli t!i2t was expetled, and if this were done, would ex- 

 ceed the bounds ufually alk'tted to a fi;igle article, we rtiall 

 only point out the moll ftriking pecuh'arities in the mufcular 

 fyftem, and correct fome errors into which other writers 

 have fallen in their accounts of this part of the anatomy of 

 birds. 



Thd mufcles 'juhich move the lower jaw, do not differ ef- 

 fentially from thofe of mammalia. There is no marked di- 

 ftinclion between the maftter and temporal mufcles ; they 

 form one ma''s which arifcs from the temporal foffa and infe- 

 rior part of the orbit, paffes under the zygoma, and covers 

 the iide of the lower jaw from the joint to the commence- 

 HHiit of the bill. 



There is a tendon which lies over the mufcles on the fide 

 of the jaws, ufually of a trianL;ular figure ; it is attached to 

 the inferior bony portions of the orbit, connects them to 

 each otiicr, and thus completes the margin of the orbit. 

 It is affixed to the protuberance on the outfide of the 

 lower jaw, near the joint, and feems to prevent the mouth 

 opening bevond a certain diilance. 



Birds have none of the mufcles of the face, js they 

 have no foft parts for them to move. 



The lower jaw is dcprelicd by a mufele which arifes by 

 two portion^, o;ie from the hollow behind the fide of the 

 tociput, the other from the furface behind and below the 

 cNtcrna! meatus auditorius ; both arc inferted upon the back 

 <j! the lower javv. This mufele, although lo unlike the dV- 

 ^ajlricus, fupplies its place, and fulfils its office. 



There are three mufcles for moving the upper jaw, which 

 are quite peculiar to birds. Thijiijl is of a radiated or fan 

 fliape ; it ariies from tlie feptum of the orbit, and palling 

 obliquely backwards, is inferted by tendon into the external 

 furface of the end of the inter-articular bone, juft when it 

 becomes joined to the articular. By pulling the pofterior 

 end of the inter-articular bone upwards, the oppofite end is 

 puihed forwards, which proJuces the elevation of the upper 

 jaw in the manner alrr;ady defcribed. 



The fecond is a ihort thick mufele, arifing from below 

 tiie poiterior part of the orbit, and before the external mea- 

 tus auditoiius, and inferted into the inner furface of the 

 body of the articular bone and its anterior procefs, where 

 it joins the inter-articular bone ; it elevates the pofterior 

 end of the inter-articular bone, and thus raifes the upper jaw. 



The //j;V,/ mufele is for deprcffing the fuperior jaw ; it is 

 of a long taper lliape, has one attachment to the infide of 

 the lower jaw, and then becomes affixed to the infide of the 

 JBter-articuIar bone, tlie internal part of the pterygoid pro- 

 cefs, and f-nds a fmall tendon to the integument of the pa- 

 late, jull where the horny covering of the mandible com- 

 mences. It is difficult to dillinguifn it from the pteiygoid 

 mufele, which appears to aid it in the depreffion ot the fu- 

 perior mandible. 



The tongue enjoys much lefs variety of motion in birds 

 than in mammalia ; it is only capable of being protruded, 

 rctraCled, turned to each fide either direftly or obliquely, 

 fii^htly rotated, and depreffcd at the point. There are a 

 great many mufcles, however, employed in the pertormance 

 of thefe motions ; fome of thefe aft upon the os hyoides, 

 and others upon the lingual bone. 



Tl»e firll is analogous x.o\}\ej}ylo hyoidetis; ariles from the 

 upper and back part of the lower jaw, divides into two flips; 

 one goes to the ilyloid bone of the os hyoides, where it 

 meets its fellow : the other flip paffcs to the inner part of 

 the middle bone or body of the hyoides ; it retracts the 

 tongue. 



Tiie fecond correfponds to the mylo-hyo'ideus ; it is a broad 

 thin mufele, proceeds from the infide of llic lower jaw, ex- 



cept its pr){lerior edge, which comes from the outer part of 

 the jaw ; it is inferted upon the concave fide of the cartila- 

 ginous extremity of the horn of the os hyoides, around 

 which it forms a mufcular (heath ; its ufe is to protrude tke 

 tongue. 



The tiiird mufele appears to anfwer to the geniohyo'idcus ; 

 it comes from the fuperior edge of the lower jaw internally, 

 and becomes attached to its fellow on the other fide upon 

 the tlyloid bone of the hyoides ; protrudes the tongue a 

 little from the obliquity of its direftion, and feems to com- 

 mence the actions of deglutition by elevating the part5 in 

 the bottom of the mouth. We did not obferve this mufele 

 in the cock. 



The fourth mufele of the tongue is extended from tiic 

 honi of the os liyoides at its root, to the ftyloid bone« 

 where it joins the miifcle of the oppofite fide. They ap- 

 proximate the honis of the hyoides, during the protrufion o£ 

 the tongue. 



The fifth is a very fmall mufele, lying along the internal 

 furface of the iiorn of the os hyoides ; it fends a delicate 

 tendon to the under furface of the lingual bone, deprcflcs 

 the point of tiie tongue, and if it aCts fingly, turns tilt 

 tongue. 



The fixth is a little fliort mufele, which arifes from the 

 end of the middle bone of the hyoides, ar.d is affixed to the 

 under part of the lingual bone ; depreffes the tip of the 

 tongue, and raife.-> the bafe. This is a fingle mufele. 



The feventh mufele lies along with its fellow upon the an- 

 terior furface of the fuperior larynx ; it is attached to tlie 

 root of the lingual bone. Its ufes are to dtprefs the bafe 

 of the tongue, and thus ekvate the point, and to retract the 

 tongue while in the mouth. 



The eighth is fliort ; arifes from the junftion of all the 

 bones of the os hyoides on the lower furf^ice, and is in- 

 ferted into the upper and outer corner of the bafe of the 

 lingual bone. It bnngs the tongue into a ilraight line, af- 

 ter the other mufcles have deprefled the tip. 



The ninth mufele is the lall ; it is very minute, and paffes 

 from the bafe of the hngual bone to the very tip of the car- 

 tilage ; depreffes the point of the tongue without elevating 

 its root. 



The mufcles which protrude and retraft the tongue, arc 

 remarkably large in the luoodpcckers and •wrymchs. 



The mufcles which mov! the head and red, are even more 

 complicated in birds than in other animals. Mod of them 

 have their attachments fo numerous and intermixed, that no 

 defcription can convey an adequate idea of them. 



The lon^us cola begins in the thorax on the anterior fpines 

 of the dorfal vertL-brs ; its fafeiculi go from the anterior part 

 of the cervical vertebriE to the ftylcsand tranfverfe proceffes ; 

 and their tendons are longeil at the fuperior and inferior 

 part of the neck. 



The reBus capitis major ar.ticus is continued from the head 

 as low as the fitth vtrtebrx of the cervical fpine. 



On the pollerior part of the fpine there is a fma'l mufele 

 which feems to reprefci.t the fnpcrior part of the trapezius ; 

 it is extended from the tranfverle proceffes of the four firll 

 cervical vertebrx to the back of the occiput ; it brinjjs thq 

 head backwards and to one fide. 



There are a great number of fafeiculi interpofed betwcca 

 the tranfverfe and articular proceffes at the back of the 

 neck. Thefe tendons pafs over fcveral vertebra; before 

 they are inferted on the middle of the neck, which is the 

 part moll bent backwards. 



A mufele which has been confidered analogous to the cer- 



riciilis d.fcea.iais, is the chief extenfor of the neck of birds. 



It arifes fro;n the fpine of the back, oppofite to the fc- 



3 I 2 coad 



