CLASSIFICATION OF MOLARS. 515 



In the second edition of the ' Lecons d'Anatoraie Comparee,' 

 of G. Cuvier, torn, iv, 1836, the * fausses-molaires' are distinguished 

 from the ' vraies-molaires,' by their fewer roots and narrower crown : 

 " par moins de racines et par une couronne moins large et conse- 

 quemment moins propre a broyer." (p. 246). And, in the Numerical 

 Tables, the molar series is divided into 'fausses molaires rudimentaires, 

 fausses molaires normales, vraies molaires carnassieres,' and ' vraies 

 molaires tuberculeuses :* the series in Man giving : 



J. 0-0 2-2 3-3 / 0^/1 N 



f. m. r. — ; r. m. n. — ; v. m. — . (p. 2o4.j 



^ 0—0 * "^ 2—2 ' 3—3 ^^ ' 



and that in the Lion or genus Felis : — 



/. m. r. — ; /. m. n. — ; v. m. c. -— ; v. m. t. —-. (p. 252.) 



•^ 0—0 "^ 2—2 1—1 0-0 ^-"^ 



Both these systems are rejected by M. de Blainville in his 

 ' Osteographie d'Aniraaux Vertebres.'(l) In this beautifully illus- 

 trated Work the molar series is divided into premolars, principal, 

 and true molars : * (avant molaires, principale et arri^re-molaires,' 

 t. I, p. 43) ; which are thus exemplified in the Human dentition : 

 the five teeth of the molar series are divided into two premolars, 

 one principal, and two true or post-molars, and, with the incisors 

 and canine, are indicated by the following notation : — 



2 15 "^ 12 



" - i. + - c. 4- - m. dont - av. m. - pr. - ar. m." (I. c. p. 43) 



215 2 I-'^2 \£-/ 



In order to determine the analogues of these kinds of molar 

 teeth, and especially the ' principal' molar, in other animals, the 

 Author gives the following definitions or characters : first, with respect 

 to form or shape, he divides the molars of Mammalia ' en avant- 

 molaires, en principale, et en arri^re-molaires, qu'importe qu'elles 

 soient simples ou complex, tranchantes, ou tuberculeuses.' {I c. p. 43.) 



As the so called principal molar of Man is not distinguished 

 by the trenchant, or any other peculiar form, M. de Blainville 

 next points out another character taken from its position in the 

 jaw. In most cases, he says, we may easily recognise the prin- 

 cipal molar, in the upper jaw, which is always the ' point de depart' 



(1) "Nous avous ete oblige d'abandonner cette classification des molaires des Mammiferes 

 et d'en etablir une autre." — Osteogr. des Mammiferes, torn. i. p. 43. 



ll2 



