1888.] 



NATURAL SCIENCES OF PHILADELPHIA. 



255 



maxillse, and the mcisive pad which is an elliptical or pear-shaped 

 body which answers to the position of the incisive foramen. 



The raphe is ordinarily composed of two parts, one of which 

 represents the median line and the other is deflected from it to the 

 left at the posterior free end. (See figs. 2, 4, 7.) 



The rugte extend back no farther than the first molar tooth. The 

 region answers to an imaginary plane which bisect the infra-orbital 

 foramina. The rugie are composed of papules which are arranged 

 in series, an arrangement which is most evident in the posterior 

 folds. The folds are smallest where the membranes are the thin- 

 nest and are the largest where they are the thickest. 



As a rule the incisive pad is in line with the raphe, but it may 

 be deflected (see fig. 3) or continued forwards between the central 

 incisors (see fig. 5). Occasionally the anterior end can be seen from 

 the front lying in the interval between the teeth named. It may 

 persist in the aged long after the loss of the incisors. When the 

 deflection is decided it enters into the causation of torus palatinus} 



Figure i. 

 The arch is wide and moderately arched. The rugse as a rule are 

 entire, — the exceptions being both first post-sutural rugx — and the 

 last postsutural on the left side. The neck folds are conspicuous. 



The largest transverse fold lies between the canine teeth or be- 

 tween them and the first bicuspid and answers to the suture between 

 the maxilla and the premaxilla. It will receive here the name of 



^ For reference to iorus palatinus see W. Sommer, Virchow's Archiv. 1883, 

 vol. 94, 21. 



