514 THE INTESTINAL CANAL, BY E. KLEIN AND E. VERSON. 



infiltrated mucosa is divided into portions resembling Peyer's 

 patches by means of connective tissue cords proceeding from 

 the submucous tissue. Acinous glands are distributed in the 

 submucous tissue, and they are in contact externally with the 

 muscular tissue of the pharynx. 



THE TONGUE. 



That^surface of the tongue in Man which is directed towards 

 the palate dorsum of the tongue presents different characters 

 from the lower surface ; for in the former the papillary eleva- 

 tions of the mucosa covered with tesselated epithelium project 

 to a considerable extent, and confer upon it its peculiar 

 furred appearance; whilst on the lower surface the papillae 

 of the mucous membrane do not in general project more 

 than to half the thickness of the epithelium. The surface 

 of the descending portion of the tongue in the newly born 

 child, again, presents different features from that of the adult ; 

 in the former, the surface of the mucous membrane appears 

 tumified, the swellings being divided by elongated fissures ; in 

 adults, on the other hand, it is beset in many places with 

 numerous smaller and larger lenticular elevations, which some- 

 times possess a small opening. The mucous membrane on the 

 lower surface of the tongue, when in the contracted condition, 

 exhibits numerous fine parallel folds like those which, under all 

 circumstances, are to be found upon the sides, posterior to the 

 level of the foramen csecum. 



The papillse freely projecting from the surface of the tongue 

 are termed, in accordance with their form, (a) filiform papillse 

 filiformes ; (6) club shaped papillae fungiformes ; and (c) cir- 

 cumvallate papillse circumvallatse. The so-called filiform 

 papillae are conical, and in the newly born are simple and 

 rounded at their extremity; whilst in adults they are compound, 

 and frequently prolonged into hair-like processes. The clavate 

 or fungiform papillse are thinner at the basis than at the apex, 

 which appears expanded into a club-like body, and in adults is 

 provided with secondary apices. 



The circumvallate papillse, lastly, are the largest, and are 

 only distinguishable from the fungiform by the wall of mucous 



