650 TOKUYASU KUDO 
4. The divergence of the median muscle edge from the middle 
of the chin amounts to 14 (9 to 19) in the negro (Chudzinski) ; 
13 (5 to 20) in the Japanese; on the right side 6, 6, 12, on the left 
side 12, 14, 15, 9 in the Chinese; on the right side 6, 10, 9, on the 
left side 12, 14, 15, 9 in the European, and according to Chud- 
zinski an average of 12. 
M. risorius (figs. 1 to 8) 
Opposite the risorius of Santorini, which arises from the trian- 
geularis, Ruge has distinguished a platysma-risorius, in which 
Forster and Loth support him. This is said to arise by a con- 
tinuous separation from the arcuate platysma bundles extending 
over the cheek toward the angle of the mouth. Such a dis- 
tinction, however, appears to have no significance, since there 
are cases where actual confirmation is difficult, even impossible. 
Such a recognition would be especially difficult in the Mongolian, 
because here the platysma bundle is directed very generally 
toward the corner of the mouth, covering the risorius. Still the 
typical platysma-risorius is occasionally present, as I have seen 
it in at least three cases in Japanese preparations. These three 
cases are grouped according to the arrangement of Blundschli, 
one (JIV) of type VI, 2 (JV and JX) of type IV. 
In the Mongolians the M. risorius is recognized, as is the tri- 
angularis, by its stronger development. My material allows the 
following arrangement. Observations on fifteen half faces of 
Japanese: 
1. Risorius lacking (fig. 8) : twice in Japanese, once in European. 
2. Risorius is weakly developed and entirely isolated from 
the triangularis (fig. 4): four times in Japanese, two times in 
Europeans. 
In JIII, JIV, and EI, EIII, platysma bundles are inserted 
between M. risorius and triangularis and have a convergent 
course, together with the former, toward the corner of the mouth. 
They may function possibly as a risorius. 
3. Risorius is spread out radially in the region of its origin; 
several intermediate bundles are present between risorius and tri- 
angularis (figs. 1 and 6): 6 times in Japanese, 2 times in Europeans, 
once in Chinese. 
