484 FRETS, THE INDEX CEPHALICUS. 
time that I was engaged with it, made it necessary, also once more 
by one or two other persons. 
In the 5 tables A—E, which are not published here, the material 
is grouped according to the number of generations that is examined 
of the families. Table A contains families of parents and children 
(two generations), table B of brothers and sisters and one or none 
of the parents.: Table C contains families of parents, children and 
One to three grandparents (three generations); table D contains 
incomplete families of parents, children and grandparents and 
finally table E contains families of four grandparents, both parents 
and children (three complete generations.) | 
Table 1 (p. 482-3) shows the variability of the headindex ofthe 
entire material. Of the whole material (N,), 3604 persons of all 
ages, the range of variability is n, — 95 — 66 = 30. The arithmetic 
mean is M, = 80.75, the standarddeviation c, — 3.11 and the 
coefficient of variaton v — 3.85. 
For the total number of 1549 men, we find the range of varia- 
bility n, — 92 — 66 = 27, the mean index M,, = 80.4, the stan- 
darddeviation 56, = 3.22 and the coefficient of variation v, = 
4.005. Bork (1908, p. 160) finds for 4600 male Dutch 19 years of 
age and upward a variability of the headindex from 68 —93 and 
for the indices 79, 80, 81 and 82 the frequenctes 534, 538, 555 
and 503, i. e. 46 9/9 of the material. 
_ For the total number of 2057 women we find n, = 95 — 70 = 
26, M, = 81.04, c, = 2.994 and v, — 3.691) (see tab. 20). 
The standarddeviation is calculated from the formula 

zp D? ; Pee a 
+ | fe according to the indications of JOHANNSEN (1913, 
n 
p. 43). 
_ Thus the mean headindex of men is in my material 81.04 — 80.4 = 
0.64 lower than that of women. The variability of the headindex 
1) With a calculation a year before we found: 
N. = 3475, M: = 80.75, ¢,°= 3.11. 
Na =01481; Mu = $80,380 4 13.22: 
IN 1904 Nw == 8102, 0402.99, 
And for GALTON’s quartils we found (cf. p. 485 ) 
for the whole material q,; = 78.11, q» (Med) = 80.14, q; = 82.16. 
for all the men q? = :71.67,.q93 (Med): "79,75, q; 816 
and for all the women q, — 78.47, qo (Med) = 80.4, qs = 82.4. 
