138 L. W. G. niichner: 



Fraipont, in order to estiiuate the forward iirojection of the pre- 

 uiaxilhiry region, introduced at the 19fKi Liege Congress of French 

 Anatomists, a new method, employed by him in his investigations 

 upon the Spy crania. The method consists in producing the glabella 

 laml)da line forwards, and then dropping perpendiculars at right 

 angles to it (Kiu. 1). The one drawn troni the glabella, usually cuts 

 the sei-ond ^jremolar, and, more rarely, the first molar, and is occa- 

 sionally known as '" Fraipont's line. The point of inteirsection of the 

 line drawn parallel to Fraipont's line, and cutting the prosthion, with 

 the glabella-laniibda line, continued forwards constitutes Klaatsch's 

 " Prognathic point '" ('2')), (Fig. 1). The distance from the glabella 

 to the '■ prognathic point " expresses, in millimetres, the amount of 

 prognathism present, that is, the amount of facial projection in front 

 of the glabella. Fraipont, from the results thus obtained, deduced 

 the fact that the amount of facial projection, or prognathism, in the 

 Spy crania, was greater than had been previously suspected (Fig. 



Thomson and Ma elver (26), consider that the method devised by 

 Flower lias several weak points, and they therefore depart from it 

 in their examination of the ancient Egyptian crania. In their pro- 

 posed method, they take into consideration two factors which present 

 themselves in the upper jaw ; firstly, the degree of variation in the 

 vertical face leng-th, that is, the nasi-prosthionic length, and secondly, 

 the variations in the horizontal length of the basi-prosthionic line. 

 By connecting three points— the basion, prosthion and nasion — a 

 triangle is formed. 



From a series of measurements of 38 skulls, these authors found 

 that the angle formed by the basi-nasal line and the Frankfort hori- 

 zontal plane varied between 22 degrees and 34 degrees, witli an 

 average of 27 degrees. They availed themselves of the constancy of 

 this angle in order to construct a new h(u-izontal, upon which to esti- 

 mate the degree of prognathism, their procedure being as follows : — 

 Prolong the basi-nasal line indefinitely downwards and backwards, 

 upon this erect a horizontal, at an angle of 27 degrees, open forwards 

 with the basi-nasal line. This line may be prolonged indefinitely 

 backwards and forwards, and the figure is now converted into a 

 triangle, by dropping from the nasion a perpendicular, which cuts 

 the new horizontal at a right angle. (See Fig. 2). The amount 

 of projection of the prosthion in front of the perpendicular line N-P in- 

 dicates the degree of prognathism, and is re;id off by means of theii' 

 specially-devised trigonometer. Fiirst (27) has also studied this 

 method, Imt he comes to the coni'hision that the liasal aniile possesses 

 so great a degrei- of variati(in that, he t-aunot, like Thomson and Mac- 

 Iver, accept a constant size for it. He savs, " Aus allem, was ich 



