M. L. Tildp:sley 
215 
taken by means of Kanke's goniometer when the skull was on the craniophor. As 
this is a measure which we find it difficult to take accurately*, I am very satisfied 
to have obtained so good a degree of correspondence in the two sets of figures. 
All the measurements of which use has been made in this enquiry into the accuracy 
of contour tracing are means of individual contour measurements; they are not 
read off from type contours, since such readings are not bound theoretically to be 
identical with the corresponding means of the individual contours. Thus any dis- 
crepancy due to this cause has been obviated. The conclusion is that contours may 
be used to replace direct measurements and can do so with great accuracy. The 
results are, however, more subject to error through the conditions under which the 
work is done, and what seems to be a very slight defect in the instrumental con- 
ditions may be considerably magnified in the tracings. 
Comparisons between Measurements on Type Contours and Means of Individual 
Contour Measurements which are not used in Construction of Type Contours. 
Males 
Females 
Types: 
A 
B 
C 
A 
B 
C 
;y „ f Mean contour value 
(Type contour 
112-6(44) 
112-6 
111-3(7) 
111-5 
113-1(8) 
113-1 
106-7(39) 
106-5 
106-0(7) 
105-9 
108-2(18) 
107-5 
-.^ J Mean contour value 
^' \ Type contour 
93-7 (43) 
93-9 
97-3(7) 
97-5 
100-2(8) 
100-0 
92-8(39) 
91-8 
91-8(17) 
91-5 
91-2(18) 
91-1 
( Mean contour value 
. 1 Tyi)e contour 
167- 9 (44) 
168- 0 
169-2(7) 
169-4 
171-4(8) 
171-3 
162-0(39) 
161-4 
160-3(17) 
160-2 
163-4(18) 
163-1 
/3 subt. j Mean contour value 
to iV\ (Type contour 
72-0 (44) 
72-4 
70-2(7) 
70-4 
70-0(8) 
69-7 
68-5(39) 
68-5 
68-0(17) 
68-2 
68-1 (18) 
68-4 
J Mean contour value 
( Typo contour 
168-7(44) 
168-9 
171-1(7) 
171-4 
169-3(8) 
169-3 
160-7 (39) 
160-7 
157-7(17) 
157-7 
164-1 (18) 
164-3 
/3 subt. j Mean contour value 
to GI (Type contour 
91-2(44) 
91-4 
90- 8(7) 
91- 2 
93-6(8) 
93-8 
85-3(39) 
85-4 
85- 7(17) 
86- 1 
86-5(18) 
86-7 
5 bag {H') ( Mean contour value 
^ ' I Type contour 
134-1 (43) 
134-7 
133- 6(7) 
134- 4 
137-5 (8) 
137-5 
128- 8(39) 
129- 3 
129-3(17) 
129-7 
128-3(18) 
128-7 
y.^^^ (Mean contour value 
■' ]Type contour 
36-8 (42) 
36-7 
35-1 (8) 
34-4 
37-1 (8) 
37-3 
34-7(39) 
34-2 
35-3(16) 
351 
35-1(18) 
34-5 
Glabella to (Mean contour value 
occiput(/y) (Type contour 
; 172-0(44) 
172-3 
174-4(7) 
174-3 
175-5 (8) 
175-4 
165-7(39) 
165-3 
162- 8(17) 
163- 0 
169-1 (18) 
169-2 
We have here 54 pairs of measurements. In only nine of these is the discrepancy 
as much as 0-5 mm., and the largest is 1 mm. As any difference between the 
results of mean individual contour values and type contour values would tend 
to show itself more in small series than in larger ones a study of this table encourages 
us to rely with some confidence on mean values as read from the type contours, 
* This difficulty was commented on by Fawcett and Macdonnell. (See Bioinetrilca, Vol. m. p. 202.) 
14—2 
