DATA FOR THE PROBLFAI OF EVOLUTIOX IN AfAX. 
•251 
where e and iq are to be determined from skull measurements, and Sj, 8 ,,, 83 give the 
mean differences between head and skull measurements. What values are to be given 
to these quantities ? 
As we have seen, the constants e and rj of (B) do not vary very much from local 
race to local race, while, on the other hand, a, /3, y of (A) differ very considerably 
from race to race. We shall hardly expect, therefore, to obtain as good results from 
(A) as from (B). Let us accordingly take (B) first, and consider 8 j, 8 ^, 83 . 
H. Welcker^ o'ives the followino- measurements for an averao-e of thirteen males 
C) o 
in middle life :— 
Thickness of flesh at back of head = G '8 millims.* 
,, ,, middle of forehead = 4’3 millims. 
., .. top of crown = 5'9 millims. 
The values at the side of the head and on the auricular orifices are not given. But 
the results seem to show an averag-e of 11 to 12 millims. to be subtracted from the 
head measurements when we wish to get those of the skull. 
MeekelI gives G millims. as an average thickness of the tissues covering the skidl. 
Thus Welcker and Merkel are in good agreement. 
We can consider this matter from another standpoint. I can find no head 
measurements from Bavarians or Badenser to compare with my skull measurements 
in Table XX., but the following table gives some results from English sources :— 
Table XXIIT. — Mean Head Measurements. 
Organ. 
Male. 
Female. 
B.A. 
Anatomists. 
U.C. Staff. 
B.A. 
B.C. Students. 
u 
198-1 
198-4 
196-38 
185-6 
189-71 
h 
1.5.5-0 
157-2 
153-48 
147-3 
146-78 
ho 
130-9 
133-1 
134-78 
128-4 
132-73 
^ (b + ^0 + ho) 
161-3 
162-9 
161-55 
153-8 
156-41 
The British Association measurements are averages obtained by myself from the 
values given for several years in the “ Beports of the Anthropometric Committee ” 
which are published in the ‘ Transactions.’;}: They cover tpiite a long series. The 
“anatomists” are the head measurements of thirty-five of the anatomists attending 
* ‘Schillers Schiidel und Todteiimaske,’ Braunschweig, 1883. 
t ‘ Handbuch der topographischen Anatomie,’ Bd. I., p. 12. 
t Repoi’ts of Committee, 1889 . . . 1893. 
2 K 2 
