124 PROF. DR. L. BOLK 



This agreement is such a striking one, that I believe it to be 

 the manifestation of a fundamental relation between the para- 

 molars and the elements of the first dentition. I think the 

 paramolars are the continuation of the elements of the milk 

 dentition which, however, during the progress of the evolution 

 of the mammalian dentition, grew rudimentary and finally were 

 elminated from the row of functional teeth. Their reappear- 

 ance in man must be ascribed to retrogression. But in order to 

 prevent misunderstanding, I wish to emphasize that the elimi- 

 nation of these teeth took place at the root of the mammalian 

 stem. Perhaps their homologues may be found still as func- 

 tioning teeth in some marsupials, with an exceptionally increased 

 number of molars. But I shall not dwell on this point. By my 

 conception of the morphological value of the paramolars, the 

 question whether our molars belong either to the first or to the 

 second dentition is solved at the same time. For if the para- 

 molars belong to the row of milk teeth, necessarily the functional 

 molars must belong to the second dentition, the set of perma- 

 nent teeth. One must not forget, however, that this statement 

 holds good only for the second and third molar, the first belong- 

 ing, as fully demonstrated in the foregoing pages, to the set of 

 milk teeth. The whole set of the so-called first dentition is 

 therefore composed in man of the following elements: the five 

 deciduous teeth, the first permanent molar, and the two para- 

 molars which appear only as individual variations. 



Arrived at this point of view, we are able to explain a phe- 

 nomenon, upon which stress is laid above, viz.: that never does 

 a first molar either in the upper or in the lower j aw show a para- 

 molar cusp or a paramolar root. This total absence of an addi- 

 tional cusp or root on these teeth appearing not very rarely in 

 the second and third molar, is readily understood The para- 

 molars are elements of the outer set of teeth, the so-called first 

 or milk dentition. They may fuse occasionally with the ele- 

 ments of the inner row, manifesting themselves as a super- 

 numerary cusp or root. But our first permanent molar itself 

 is an element of the outer set of teeth, therefore a paramolar 

 tubercle on this tooth is a quite unimaginable thing. 



