TONGUE. 



a certain oral species also, as in the common whelk (Buc- 

 f the orders, dnum undatum), it is recurved (fig. 7o9. A, 2). 



has received by common consent the name p- 759^ 



of lingua, I shall briefly describe it. The 



mouth of insects is furnished with two lips 



an upper lip, or labrum, and a lower lip^ 



or labium ; besides four jaws a mandible,' 



or upper, and a maxilla, or lower jaw, on each 



side. The labium, or lower lip, is divisible 



into two parts a mentum, or basal joint, 



and a more flexible piece moving on this, the 



ligula, or labium proper. On the inner sur- 

 face of this labium is developed a small pro- 

 cess having a certain resemblance to a tongue, 



situated in front of the cesophageal orifice, ^ ^ ^ CLl ^ Ui swuu 



and generally anchylosed with the labium at 8h ^ g 'J^ 1 ^Sve" posito ^ihT'm^Q^"^; 



the front and sides of that opening ; in some tongue, 6; and oesophagus, c. 



cases, however, as in the locusts and dragon- 2. Retracted proboscis of Buccinum undatum. a, 



flies it is free. This process Cuvier con- mouth; b, tongue; c, oesophagus. 



/ ' . * n . i i i _ . .. J "R ainrrlo rmir /vf tr^nn-no-tootVi r\f 



rf ^ .^ ^ 



B, single row of tongue- teeth of B. undatum. 

 This membrane is covered on its upper sur- 



sidered merely us a part of the labium, and 



accordingly called it labium; Fabricius and _ ___ w ^ _ _ u 

 Latreille gave it the name of hgula. In shape face wjth transyerse rowg of minute ^ 

 it is generally short but in bees it long ; it rather , ateg w - th tubercular or too thlike pro- 

 is frequently simple, but in the wasp its apex cesses r. them> The number of ^ . g 

 is trifid, the same m Melolontha stigma; i ^^g^ and very variable, the terrestrial 



or 



Canabus it possesses three short teeth; Jes av j probably, about eighty, and 



Elaphras it terminates in a single tooth or Jg marine **^ oft , man m 8 or ^. the 



gubject 



marne 

 point. In substance it generally approaches number of 



to a cartilaginous consistence, but in the Ortko- 

 ptera and Libellulfs it is much more fleshy : 

 and in the predaceous beetles it is as hard 



row 



greater variation : the common whelk 

 cinum undatum) has but three (fig. 759. 

 the large garden slug (Limax maximus) 



sume most complicated and elegant forms 

 (fig. 759. B). The centre plate of the row is 

 s symmetrical, and its denticular projec- 



present such an endless variety of forms, that 

 the most that can be said of them, generally, 

 -D is that the dental processes point backwards. 

 Fig. 759. B represents a row of the denti- 



I- . -w- - i - / 7j M*C 1I tlv^ tlCil V*U.ll BBtJUL \JL-JlllblAlA' II 'i*w t 



and horny as the integument. In some cases hag lg(X The gh of the lateg |n terreg _ 

 it is immovable, m others projectile and re- iM t oda is usually i rregu larly qua- 

 tractile within the mouth ; in some cases dran fo ular> sl f ghtl longer than broad> while in 

 smooth, m others covered with hairs as is gome fluviatile and marine species they as . 

 the case in the common hive-bee ; in Melo- 

 lontha stigma the hairs are incurved In the 



hive-bee the upper part of the tongue is car- ^ B>llulJClIii;ai , nuu 1LO UCIIltt;ui , FIWJ ^- 



tilaginous, and remarkable for a number ot tiong Jnt jn the direction of the closed end> 



transverse rings : below the middle it consists ^ e backwardsj and nearl horizontally. The 



of a membrane longitudinally folded m in- , tes Qn either gide of thjs central late usu . 



action, but capable of being inflated to a con- assume in terr estrial gasteropods much 



siderable size : this membranous bag receives tfae game form and directionf while some of 



the honey which the tongue, as it were, laps the fluviatile and most of the marine species 

 from the flowers, and conveys it to the 

 pharynx.f 



Mollusca. Gasteropoda. In the acephalous 

 mollusca there is, of course, no tongue, 



the Gasteropoda are provided with a very sin- ~ us ton gue-plates of the Buccinum unda- 



gular apparatus, which, since it is usually called fum , there &re geen fco be Qnl} . three . the cen _ 



the tongue, cannot be allowed to pass obser- tra] Qne symmetr i ca i } t h e lateral ones of very 



vation here, though its right to such an ap- different form> individually non-symmetrical, 



pellation is somewhat questionable. Its torm bu( . having an exact correspondence to one 



is subject to much variation, but it may be another> The tongue itself (^ 759. A, 2) is 



described generally as a thin membrane, long attached> as before stated> to the oesophagus 



and narrow, the greater extent ot which is neaj . itg anterior extremity, and lies beneath 



rolled into a tube. This tubular part (Jig. 759. ^ Jn the Hdices and Limaces it is enveloped 



A, 6), occupies the posterior portion of the Jn fhe muscular head of the gas teropod (fig. 



membrane, the end being closed, while its an- ?39 ^ ^ itg posterior blind end being j ust 



terior extremity is open and in connection vigjble at the back part of the head> some dis _ 



with the oesophagus ; in front ot the tubular fcance bdow the mt where the esophagus 



part of the tongue is a continuation ot the leayes th&t rt and passeg into the abdoraina i 



same membrane, which is here flat, and in many cavity In the wbe j k tr j be i t u es beneath, and 



parallel to, the oesophagus, and is free, though 



* Ce qu'on a nomme langue dans les cole'opteres surrounded by strong" muscular bands, the 



et les orthopteres, ou 1'extremite' membraneuse de la genera i direction of which is also parallel to 



levre inferieure, en merite a peine le nom. Cuv., to . . . , . .1 . .1 



Lecons d'Anat. Comp., t. iii. p. 347. 

 f Kirby and Spence, vol. iii. p. 453. 



the tongue. It is in this tribe that the an- 

 terior end of the tongue is curved downward, 



