640 TOKUYASU KUDO 
poral direction (pars aberrans ascendans). The latter section 
radiates at various elevations near the region of the cheek. 
I have found in five Japanese and two Chinese? (figs. 1, 3, 4, 
6, and 7) well-developed fibers which cross a line drawn from the 
corner of the mouth to the outer auditory opening, but I have not 
found these in European heads. The platysma which reaches 
this line has been observed in four Japanese and three Euro- 
peans.*? J have observed in six Japanese (fig. 5), a Chinese (fig. 
2), and two Europeans (fig. 6)‘ a lesser extension of the muscle, 
which usually exists as the pars labialis and does not reach a line 
drawn from the corner of the mouth to the auditory organ. 
I have arranged these three developmental stages after Loth, 
as follows: 
JAPANESE CHINESE NEGRO EUROPEAN 
(KUDO) (KuUDO) (LOTH) (KUDO) 
HFONg 58 22.0 GES Le REET. 5 4 18 0 
Mediumeee ones ees 4 0 6 4 
\GEy eee traps dia are on ey eee Ten 6 2 2 3 
Number of half faces...... 15 6 26 7 
The radiating form of the cheek division of the platysma is 
subject to many variations. These have been arranged by 
Bluntschli-Loth in the following series of types: 
I. Usually transverse course of the upper platysma-fibers 
(fig. 8). 
Ia. Weakening of type I. 
The above two types belong to a primitive group. 
II. Acquisition of an ascending direction of the fibers with loss 
of the transverse. Pars aberrans ascendans is well developed 
(figs. 1, 4, 6, and 7). 
Ila. Pars aberrans is lost or only weakly developed. 
III. Strengthening of pars labialis after loss of pars aberrans 
(fig. 5). 
IIIa. Weak development of the platysma, the fibers of which 
hardly extend over the edge of the mandible. 
2 JII, JIV, JVI, JXI, JXV, and CII, CII. 
8 JVII, JIX, JX, JXV, and EIII, EIV, EV. 
‘JI, JIL, JIV, JV, JX, FXII, CI, and EI, EII. 
