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ANATOMY AND PHYSIOLOGY OP 



proof of it, however, than what happens in 

 hemiplegia, a disease in which only one 

 half of the body is paralytic : under these 

 circumstances, in the human subject, the 

 patient can only see with one eye, use one 

 arm, and taste with but one (and that the 

 correspondent) side of the tongue. 



" Division. — The tongue, in description, 

 is commonly divided into root, body, and 

 apex : by the attachments of the two former 

 it is held in its situation ; the latter is loose 

 and unconnected. 



" Attachment. — At its root, it is deeply 

 and firmly inserted by several muscles which 

 arise chiefly from the os hyoides and the 

 inferior maxilla : it is also connected with 

 the pharynx, and with the soft palate. 

 From the sides of the lower jaw, separate 

 layers of the membrane of the mouth are 

 reflected upon its body, forming by their 

 junction a sort of bridle,- which is thence 

 extended to the symphysis : to this part, 

 which serves to restrain the organ in its 

 motions, the name of frcenum linguce has 

 been given. 



" Papilla. — The dorsum or anterior sur- 

 face of this organ has a peculiar covering, 

 which, though it appears to be continued 

 from the buccal membrane, is a different 

 structure altogether, and serves quite a 

 different purpose. The surface of it is 

 roughened, possessing a villous texture, 

 everywhere studded with numerous little 

 conical eminences, called papilla;, which are 

 supposed to be formed out of the extremi- 

 ties of the nerves, and to be the especial 

 seat of the sense of taste. These papillsB 

 vary in size and figure, and are more abun- 

 dant and larger upon the base and along 

 the sides of the organ. Interspersed with 

 them are a number of mucous follicles, 

 whose apertures may be seen with the naked 

 eye, through which a mucus is discharged 

 upon the papillary surface, keeping it con- 

 tinually moist, and rendering its perception 

 of taste more acute. 



" Structure. — The tongue is said to pos- 

 sess a covering of common integument ; 

 and certainly its strong, compact tunic has 

 all the appearances of skin, and presents 



the common tests of it : the external layer 

 is laminated, is bloodless, is insensible ; the 

 internal or substantial part is tough, fibrous, 

 vascular, and sensitive, in fact, is like cutis ; 

 and the intermediate or connecting material 

 is delicate, soft, ond reticular, and forms a 

 bed for the lodgment of the papillsB. The 

 substance of the tongue itself consists of 

 an inter-union, or rather an incorporation, 

 of its muscles, the fibres of which intersect 

 one another, and take a variety of direc- 

 tions ; but intermixed with them is a fine 

 adipose tissue, to which is owing the flabby 

 softness of the organ, and the peculiar 

 aspect it exhibits when cut into. 



" Use. — Though the tongue is empha- 

 tically denominated, from its essential char- 

 acter, the organ of taste, it is not the only 

 part that possesses this faculty ; for the palate, 

 the pharynx, and the oesophagus, it is be- 

 lieved, participate in it. The tongue, in 

 addition to possessing this faculty, disposes 

 of the food during nianducation, and, when 

 sufficiently masticated, coUects and thrusts 

 it, portion after portion, into the pharynx ; 

 and furthermore, at the time the animal is 

 drinking, it is not only employed as an in- 

 strument of suction, but also as a canal 

 along which the fluid ascends into the 

 pharynx. 



" Organization. — Every part of this or- 

 gan is plentifully supplied with blood. Its 

 arteries are the lingual, branches of large 

 size from the external carotids. The blood- 

 vessels of either side are generally found 

 free from anastomosis with one another ; if 

 either of the arterial trunks is filled with 

 injection, it rarely happens that the opposite 

 half of the organ receives any coloring from 

 it. Its nerves are the ninth pair, which run 

 to the muscles, and a considerable branch 

 from the fifth pair, in whose extreme rami- 

 fications, which are distributed to the papillae, 

 the perception of taste is supposed to be 

 inherent. 



"OF THE SALIVARY GLANDS. 



" Number and Names. — The salivary 

 glands, properly so called, are six in number, 

 three upon each side of the head ; the 



