Prog tiathism of Tasinanimi Ahor/(/l ixil. 



IH7 



views do not ajri'ft^ witli tliost- of IIunIcv. He says, ' lliixlry !:'liiul)te 

 (lie Neiufutig iiiit deiii I'ro<riiathisnius in Verliinduniz' l)rin<r<'n /.n 

 kiinnen. Die Steilheit der Stelhmt:' soUte in «ileiL-heni Masse wie die 

 lot/tere wachsen. In unseren Tabellen tindet sicli keiiie I'.csiJitiL^ung 

 dieser Ansitht." Hopf (17), Darwin (IS), (19), Spencer (20). Keith 

 (21), Duckworth (22), Wiedersheini (2:5), Schaafhausen (2-i), have 

 each and severally considered the successive stages of growth of the 

 maxillary region, and the reasons therefor, in order to determine, if 

 ]iosKihle. the causes which produce or accompany an increase or 

 reduction, as the case may be. in the amount of prognathism present. 



Without pursuing further the subject of factors responsible for prog- 

 nathism, and their association with other cranial features, it should 

 be sufficiently clear that much attention has been devoted to both 

 aspects of the question, and that mir knowledge of the sul)ject is 

 correspondingly enhanced. 



Of the uKidern methods of determining prognathism by direct 

 linear measurements, mention may first be made of F'lower (9), who 

 calculated the prognathism of the skulls in the Museum of the Royal 

 College of Surgeons. London, l)y what is now knijwn as Flower's 

 (inathic, or Alveolar Index — an index which expresses the ratio 

 which the basi-nasal line bears to the basi-prosthionic line, the 

 former being taken as lUD (see Fig. [.). 



Fig. I. — Illustrating Flower's Gnathic Index, and Fraipont's Methods. 

 (i:=Glabella : Pr= Prognathic point : N=:Nasion: Ba^Basion: 



L=: Lambda. 



