REPTILES. 



of the tongue ; where they meet the hyoglolfi, with which 

 their fibres are interwoven. 



5. The tranfvcrfc genio-glofli are attached to the arch 

 of the chin, and to the anterior part of the inferior max- 

 illary branches, on the outfide of the preceding. Inftead 

 of being narrow and elongated, tiiey are broad and (hort. 

 Their fibres pafs obliquely from without, inwards and back- 

 wards upon the membrane of the mouth, as far as the fides 

 of the tongue ; which they will draw outwards and for- 

 wards. The two laft pairs of niufcles do not exift in the 



cameleon. ^ r • 



4. The proper mufcle is found in thofe faurians 

 only, whofe tongue admits of elongation. It is compofed, 

 in general, of annular fibres. In the gecko fimbriatus, 

 which has a broad tongue, this mufcle is divided in front into 

 fix or eight fmall portions, whicli arc united into two to- 

 wards the middle third of the tongue, and then into one on 

 fach fide, which form the two pieces of the bafis of the 

 tongue. 



In the cameleon the annular mufcle is very thick, and 

 forms a flefty cylinder furrounding the anterior three- 

 fourths of that part of the os hyoides which penetrates into 

 the tongue. Towards the front it is divided on the fides 

 into two portions, a fuperior and an inferior ; the latter is 

 folded back towards the iheath of the tongue, to which it 

 adheres. There is, moreover, a mufcle proper to this (heath, 

 which may be called the retradtor mufcle. It comes from 

 below the -dandular part, and is continued, on each fide, as 

 far as the part that i< puckered up. When the hyogloifus 

 throws this latter part into wrinkles, and Ihortens it, and 

 the OS hyoides is carried backwards by the fterno-hyoidei 

 and ceratoidei, the retraftor mufcle caufes the end of the 

 fheath to remain applied to the extremity of the annular 

 mufcle which recedes, becaufe then its poilerior attachments 

 are the moft fixed : on the contrary, when the extremity of 

 the OS hyoides and the annular mufcle pulh the (heath for- 

 wards, the anterior attachments have a point d'appui ; the 

 pofterior portions of the retractor draw forwards the (heath, 

 and unfold it. 



By putting together what we have faid concerning the os 

 hyoides and its raufcles in the cameleon, in a former part 

 of this article, and what we have juft faid of the mufcles of 

 its tongue, it will be eafy to underltand how this organ 

 can be elongated, and withdrawn into the mouth. The 

 firft office is performed by the annular mufcle, with the 

 cerato-maxillary, and the genio-hyoidei. The fterno-cera- 

 toidei and hyoidei carry backwards the os hyoides, at the 

 fame time that the hyogloflus ftiortens die (heath and puck- 

 ers it up. 



In moft of the ophidians the tongue is inclofed in a mem- 

 branous fheath, which opens behind the interval of the 

 branches of the lower jaw, and is continued backwards be- 

 tween thofe ofthehyoid cartilage, under the trachea. It 

 is Hned internally by the membrane of the mouth. This 

 fheath is carried forwards by a pair of mufcles analogous to 

 the genio-glofli. They derive their origin by two portions, 

 one of which comes from between the two branches of the 

 lower jaw, the other from their extremity ; they come toge- 

 ther and are fixed to the fides of the liieath to its moft 

 diftant extremity. The hyogloffi are two elongated muf- 

 cles, contiguous, and even united together by fine cellular 

 laminas. They exadly fiU the interval of the cornua of 

 the hyoid cartilage, and ara even doubled backwards round 

 their extremity. Thefe mufcles go to the bafis of the 

 (heath, and dra^v it backwards, when it has been carried 

 forwards by the two firft pairs. 



The proper mufcle is farmed of two cylinders, firft lying 

 6 



together, and feparated towards the anterior third of the 

 tongue, for the two portions of which its apex confiftt ; 

 hei'e they become confiderably dimini(hed, and are reduced 

 to a mere thread at the end. 



This fimple apparatus, combined with that of the os 

 hyoides and its mufcles, gives to the tongue of the ferpent 

 that wonderfully quick power of extenfion and retraction. 

 Carried forwards by the genio-vaginal mufcles, brandiihed 

 by its proper mufcles, it re-enters the fheath in confequence 

 ot the elafticity of the hyoideal cornua, which tend to reftore 

 themfelves, and of the action of the hyogloffi. One or other 

 of thefe adtions is afiifted by the cofto-maxillary mufcles, 

 according as the portion analogous to the fterno-hyoideus, 

 or that which correfponds to the cerato-maxillary, con- 

 trails. The extenfion of the tongue out of the mouth is 

 fo much the greater, becaufe it is eifefted through an 

 orifice near the extremity of the fnout, and becaufe its 

 bafis may be brought near to this part. 



In the amphifbaena;, which have a flattened tongue, not 

 inclofed in a fheath, nor fufceptible of extenfive motion, 

 there are, i ft, two genio-gloffi attached to the arch of the 

 lower jaw, more internally than the genio-hyoidei ; 2dly, 

 two hyogloffi ; and 3dly, two cerato-gloffi, wliich prelent 

 nothing worthy of particular notice. 



The tongue of the batracians, as we have already 

 defcribed, is fixed in front to the arch of the lower jaw, 

 and free behind. In pafTrng out of the mouth, and going 

 back again, it turns upon the fixed point of its attachment 

 to the jaw. Two pairs ot mufcles, the genio-gloffi, and 

 the hyogloffi, execute thefe motions. i. The hyoglolfi 

 form, in the rana ocellata, two cylindrical maU'es, lying on, 

 and attached to, the pofterior cornua. They foon unite 

 into a fingle raais, which refts on the hyoideal plate, and 

 penetrates the tongue in front of this plate, expanding into 

 fmall fafcicuh, which reach to the loofe edge of the organ. 

 2. The genio-glofli form at firit two fmall fpherical 

 mafies, placed at the arch of the chin on the fmall tranfverfe 

 mufcle ; they are fubfequently elongated into two conti- 

 guous cylinders, of which the fibrous fafciculi leparate from 

 each other, decuffate with thofe of the preceding mufcle, 

 and go to the loofe edge of the tongue. While the tongue 

 is in the mouth, the hyogloffus is folded on itielf, and the 

 genio-gloflus is ftraight. The latter mufcle is folded, and 

 the former ftraight, when the tongue has been projefted. 

 In the common frog, thefe two pairs of mufcles are not fo 

 minutely divided in the tongue, and the genio-gloffi do not 

 form fpherical maffes towards the arch of the chin : in other 

 refpefts they are fimilar. 



Tongue of the Crocodile. — Humboldt has obferved a pecu- 

 liar mechanifm in the tongue of this animal, bearing an evi. 

 dent relation to its wants and habits, of which the following 

 is a defcription in his own words. 



" From the moft ancient times difputes have exifted 

 concerning the tongue of the crocodile ; fome naturalifts 

 pretended that it was entirely wanting, others affirmed that 

 it was very (hort, and placed at the entrance of the cefo- 

 phagus. According as one or the other of thefe opinions 

 prevailed, the fculptors and antiquaries of Rome amufed 

 themfelves with deftroying or reftoring the tongues of 

 their crocodiles. When we examine attentively the os 

 hyoides of this animal, we find that it is in confequence of 

 its form and fmall iize that a part or ratlier a fold of the 

 tongue has been confounded with the whole organ. There 

 ii in this animal a peculiar mechanifm, by which a valve is 

 formed, interrupting the communication between the mouth 

 and throat. AVheii the crocodile appears motionlefs on 

 the bank of the river, with the jaws opened at an angle of 



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