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



The epithelium of the mucous membrane in the portions 

 immediately adjoining the nasal cavity is laminar and tes- 

 selated. This form of epithelium extends, according to 

 Schmidt,* to the posterior edge of the so-called pharyngeal 

 tonsils, but their anterior portion, as far as the orifice of the 

 Eustachian tube, possesses a columnar and ciliated epithelium. 

 The distribution of the latter in the regions in question is 

 most extensive in the new-born child, extending here over the 

 whole of the upper portion of the pharynx, known as the 

 cavum pharyngo-nasale. In the adult, on the other hand, it 

 never extends over more than the upper third. Both the 

 epithelium and mucosa are similar in their characters to the 

 same structures of the soft palate. 



The free surface-)- of the nasal region of the pharynx, 

 occupying the interspace between the Eustachian tubes, and 

 extending from the posterior portion of the roof of the nasal 

 cavity to the anterior border of the foramen magnum, exhibits 

 in most instances a delicate longitudinal striation, with laminae 

 or folds separated by deep fissures, which to some extent 

 become united, giving rise to a plexiform pattern ; and fre- 

 quently the surface is covered with low elevations, traversed 

 by a variable number of short, often irregularly running 

 fissures. These folds exhibit numerous whitish, poppy-seed- 

 like enlargements, with a considerable number of roundish 

 pores, which are partly recognisable as the entrance to little 

 isolated pits of the mucous membrane, but are chiefly the 

 orifices of acinous glands. 



A larger opening, though not constantly present, is found in 

 the lower half of the median line of the roof of the pharyn- 

 geal cavity. It constitutes the entrance to the process of the 

 pharyngeal arch which ascends to the body of the occipital 

 bone, and is usually surrounded by acinous glands, but some- 

 times also by a muscle. It has been named by J. C. Meyer 

 the Bursa pharyngea. 



* Schmidt, loc. cit. 



t Luschka, Das adenoide Gewebe der Pars Nasalis des menschlichen 

 Schlundkoppes, " The adenoid tissue of the nasal portion of the Pharynx 

 of Man ; " Archiv fur wissenschaftliche Anatomic, v. Max Schultze, Band 

 iv., Heft 1, Seite 59. 



