PKOKLEMS OF HIMAN DENTITION 119 



distally from it, and never with that niesially. The sohition of 

 this problem is a veiy simple one. However, to take up the 

 question now would be a digression and I therefore prefer to re- 

 turn to it at a more suitable place. 



In the foregoing, the principal points concerning the para- 

 molar cusps in the upper jaw are established, and we shall now 

 continue examining the corresponding occiu'rences in the lower 

 jaw. I recall that never have I found a free paramolar in this 

 jaw, a fact evidently harmonizing with the rule that su})ernumer- 

 ary teeth in the mandible are commonly much more rare than 

 in the maxilla. On the contrary I have met witli several co- 

 alesced paramolars in the lower jaw. 



In comparing the usual features of the coalesced paramolar 

 in the lower and upper jaw with each otlier, one is impressed l)y 

 the remarkable difference in the behavior of this supernumerary 

 element in the two jaws. 



When a paramolar-cusp occurs in one of the lower molars, this 

 tubercle frequently proves its original significance a^ an inde- 

 pendent tooth by the possession of a normal root. In the upper 

 jaw this is a very rare occurrence. I shall term this root 'para- 

 molar-root.' Now in the lower molars often only the i^aramolar- 

 root is present whilst the tubercle, i.e., the crown of the para- 

 molar, is entirely absent. In the upper jaw on the contrarv, 

 just the reverse happens. Here the paramolar tubercle is often 

 found without any vestige of a root, the latter being entirely 

 fused with the anterior buccal root of the molar. In case of 

 concrescence in the upper jaw the paramolar manifests itself 

 usually by its crown, as the pai'amolar-cusp in the lower jaw, 

 on the contrary, by its root. I ha\ e no theory whatever regard- 

 ing the cause of this singular difference in the behavior of the 

 upper and lower paramolars. In figure 15 some twenty lower 

 molars are represented, provided with a paramolar root in differ- 

 ent degrees of development. In the toj) row no paramolar 

 tubercle is to be noted, yet we observe how the paramolar root 

 gradually becomes longer and stronger, until in the last molars 

 of this row it is as long as the two normal roots. The second row 

 is composed of seven molars in wliich the ]:)aramolar root is even 



