468 Mr. Morgan on the Anatomy 



wards behind the tongue, with the muscular structure of which 

 its fibres at the lower part intermix. Each muscle ascending 

 from behind the root of the tongue passes on the side of the 

 funnel between the two layers of mucous membrane, forming 

 the anterior and .posterior surfaces of the velum, its fibres be- 

 coming more diffused and spreading over the upper part of the 

 velum to join above the funnel with those of its fellow on the 

 opposite side ; the superior termination of the two muscular 

 columns thus intermixing appears to be insensibly lost upon the 

 palative membrane. 



The two muscles are connected with a thin circular band of 

 muscular fibre, which forms an anterior sphincter to the circum- 

 ference of the funnel. On the posterior part of the velum a 

 lateral support is afforded in the same way by a band of muscle 

 on each side, which having an attachment above to the palate 

 is continued downwards, to terminate by intermixing with the 

 muscular structure of the pharynx. These two posterior slips 

 of muscle are connected above and below the aperture in the 

 velum by transverse fibres. 



To the four supporting muscles which I have now described, 

 and which may perhaps be considered as analogous to the pil- 

 lars of the fauces in other animals, the circumference of the 

 funnel will be found attached by the connection of its muscular 

 fibres with those already described : these are arranged in a 

 circular order, and form a complete sphincter over the whole 

 cone, by the contraction and dilatation of which the passage of 

 any substance through its central aperture must be assisted or 

 prevented. 



It will be seen by the drawing in which these parts are re- 

 presented (Tab. XXX.), that when any substance is passing 

 from the mouth to the pharynx, the conical projection of the 

 velum must necessarily pass over the epiglottis, and thus prevent 



the 



