PULPS AND SACS OF THE HUMAN TEETH. 3 



geal cavity into a superior and an inferior compartment. The 

 upper wall of this common cavity was smooth and flat pos- 

 teriorly (g) ; but anteriorly it was contracted and terminated 

 in a longitudinal bar (Ji), which ran forwards to be attached 

 to the superior surface of the horse-shoe lobe at the median 

 line, and to the other parts in that neighbourhood. Under 

 the bar Qi) a deep cavity (i i) was seen, which communicated 

 with the exterior of the face by two small foramina, which 

 constituted at this period the whole external nasal organ. As 

 before-mentioned, a groove (&) was observed between the lip 

 (a) and the external edge of the horse-shoe lobe (c). This 

 groove (b) was deep, and its walls and lips were in close 

 apposition. It terminated posteriorly on each side (k Jc) by 

 becoming more shallow, and curving backwards and inwards 

 on the inferior surface of the membranous folds (e e). There 

 was a median frenum between the lip and the horse-shoe 

 lobe. 



Lower Jaw. The under lip (a, Fig. 3), resembled the upper, 

 and was separated along its whole 

 extent by a groove () similar to 

 the one above, from a semicir- 

 cular lobe (c). Anteriorly this 

 lobe (e) was divided into two 

 median large (d d), and two la- 

 teral smaller lobules (e e), the whole being firmly adherent 

 to the floor of the mouth in front of the tongue and its 

 frenum, which were both well developed. The lateral parts 

 of the lobe (c) were rather indistinct, but at the point where 

 the free edge of the lip terminated, it extended transversely 

 and posteriorly, became thick and bulbous (//), and exhibited 

 on its surface a narrow shallow groove of a sigmoidal form (g g), 

 which was continuous with the groove behind the lip. There 

 was a median labial frenum. 



On the external sides of the membranous folds in the 



