652 TOKUYASU KUDO 
M. transversus mentt 
With regard to the frequency of this muscle, according to 
accounts of Thiele, Schmidt, and LeDouble, fifty-six cases (60 
per cent) in ninety bodies have been found with the muscle 
present (Hisler). But the number is too high according to 
Eisler, because it encloses radiating bundles of the platysma and 
triangularis. The muscle occurs eight times out of twenty-one 
heads in the negro, according to the computation of Loth. Fetzer 
failed to find the muscle only once in seventeen Hottentot heads, 
twice it was only rudimentary. In the Japanese and Chinese 
the muscle was present without exception; but twice it was only 
vestigial. Birkner found the muscle readily demonstrable in the 
Chinese head. It is evident, then, that the muscle is more 
generally present in the Mongolians and Hottentots than in the 
Europeans and negro. 
The relationship of the transversus to the triangularis and 
platysma is variable. In the Japanese the muscle is at times 
derived entirely from the more anterior triangularis fibers, which 
run in an arcuate manner along the submental region; more 
frequently (six Japanese heads) the triangularis fibers pass over 
in part into the transversus. Eggeling has observed a similar 
condition twice in the negro. The muscle is often entirely iso- 
lated, or occasionally inserted at both ends into the edge of the 
under jaw through the platysma fibers. This muscle has been 
observed twice in the negro (Eggeling and Loth) without a con- 
nection with the triangularis. 
The development of the muscle is computed by its breadth, 
which on the average amounts to: 7 mm. in the negro (Eggeling 
and Loth); 5 mm. in the Japanese; 3, 4, 5, 4, 2 mm. in the Euro- 
pean, and 3, 5, 3 mm. in the Chinese (Kudo). 
M. quadratus labii superior (figs. 1 to 8) 
All authors state that this muscle is less frequently divided 
into three portions among colored races than in Europeans 
(figs.6and8). Fetzer, on the other hand, notes no peculiarities 
among Hottentots. 
