MASTICATION AND DEGLUTITION./, 75 



however, when sound, may be sufficiently closed by the transverse 

 and oblique arytaenoid muscles, independently of the epiglottis. 

 Dr. Magendie says that he saw two persons perfectly destitute of 

 epiglottis, who always swallowed without difficulty." Targioni 

 also met with one, and in that case neither deglutition nor speech 

 was impaired. * 



" Deglutition is facilitated by the abundance of mucus which 

 lubricates these parts, and which is afforded not only by the 

 tongue, but by the numerous sinuses y of the tonsils and muci- 

 parous cryptae of the pharynx. 



" The oesophagus, through which the food must pass pre^ 

 viously to entering the stomach, is a fleshy canal, narrow and 

 very strong, mobile, dilatable, very sensible, and consisting of 

 coats resembling, except in thickness, the coats of the other parts 

 of the alimentary canal. 2 



" The external coat is muscular, and possesses longitudinal 

 and transverse fibres. 



" The middle is tendinous, lax, and more and more cellular 

 towards each of its surfaces, by which means it is connected with 

 the two other coats. 



" The interior is lined, like all the alimentary tube, with an 

 epithelium analogous to cuticle, and is lubricated by a very 

 smooth mucus. 



" This canal receives the approaching draught or bolus of 

 food, contracts upon it, propels it downwards, and, in the case of 

 the bolus, stuffs it down, as it were, till it passes the diaphragm 

 and enters the stomach." 



Professor Halle observed in a woman, the interior of whose 

 stomach was exposed by disease, that the arrival of a bolus of 

 food in the stomach was followed by an eversion of the mucous 

 membrane of the resophagus into it, as we notice in the case 

 of the rectum when a horse has finished discharging its faeces. a 



u Magendie, Precis Element. 

 x Morgagni, xxviii. 13. 



y " B. S. Albinas, Anotat. Acad. .1. m. tab. in. fig. 1; n." 

 z " See Math. Van. Geuns, Verhandelingen van de Maatschappye te Haarlem^ 

 t. xi. p. 9. sq. 



" Jan. Bleuland, Observ. de Structura (Esophagi. LB. 1785. 4to." 

 a Magendie, Precis Ettmentaire. 



