CURVE OF SPEE IN MAMMALS 
187 
two measurements and the value of the "center angle" of the curve 
of Spee. 
As was indicated in section VI, I measured the dental index (which 
represents the relation between the size of the teeth and of the skull), 
with the results given in tables 2 to 16. From these data I failed, 
TABLES 21 AND 22 
Data Pertaining to the Dental Index, and the Length of the Radius or the 
Curve of Spee. Arranged According to the Diminishing Values 
FOR THE Dental Index 
table 21 
Primates 
NAME OF SPECIES 
DENTAL INDEX 
RADIUS 
degrees 
cm. 
55 
10.17 
54 
7.43 
52 
7.82 
48 
6.02 
Man 
45 
7.55 
Semnopithecus femoralis 
40 
5.94 
40 
5.50 
table 22 
Simla salyrus (orang utan) 
Simia satyrus (orang utan) : 
5646* 
62 
8.03 
2223 
60 
9.46 
2172 
58 
6.68 
7064 
57 
5.51 
2170 
55 
6.58 
1563 
54 
8.38 
2222 
53 
7.35 
*Number of the skull of Simia satyrus. 
also, to find any relation between that index and the value of the 
"center angle" of the curve of Spee. For example, in table 2, speci- 
mens 5646 and 2222 have nearly the same value for the "center angle" 
(the former 34.3 degrees, the latter 34.2 degrees) while the dental 
index of these specimens is different, the former being 62.0 degrees, 
and the latter 53.0 degrees. I also failed to find any relation between 
that index and the degree of curvature of the curve of Spee, which 
