374 Recefit Studies of the Inherita7ice Factor in Insanity 
TABLE VIII. 
Showing Anticipation in Age at Deatli. B. Mothers and Children. 
(Reigning Houses iu Europe — 18th Ceutur}'.) 
! Age at Death 
Mothers 
First-born 
Children' 
Mothers 
First Sons to 
have Children 
0— 0 
10— 1 'J 
20 — 39 
80—39 
JiO-1,9 
60—69 
70—79 
80—89 
90 and over 
2 
47 
49 
43 
52 
80 
52 
18 
2 
122 
13 
26 
22 
32 
'j'j 
42 
36 
17 
1 
21 
30 
25 
■^<) 
'JrJ 
52 
41 
10 
1 
— 
8 
16 
41 
40 
46 
54 
14 
1 
Totalis 
345 
345 
220 
220 
Percentage dying under 30 
•6 
39-1 
•5 
0 
Average Age at Death . . . 
53 
35 
55 
59 
Anticipation 
18 
-4 
each case to have cliildieti, then the sons live four years longer than their mothers. 
It would have been better iu this case to have compared the mothers with the 
first daughters to have children but unfortunately von Behr gives very little 
information regarding the female lives, except in special cases. The figures show 
a marked anticipation in age at death when we directly compare, as Dr Mott 
has done, mother and child, but this vanishes when we remove the arbitrary 
selection. The same facts are shown graphically in Figs. 9 and 10. 
If we combine these figures we can compare the age at death of parent and 
child and the results are shown graphically in Figs. 11 and 12. 
Fig. 11 shows that Dr Mott's limitation of one of the two generations he is 
comparing to adults, without imposing a similar limitation on the other generation, 
introduces an artificial and spurious anticipation. The average age at death of 
the parents is 56 years and of their first-born children only 35 years — so that we 
get an anticipation of 21 years. If, however, we make the two generations 
almost directly comparable by dealing only with sons who have children — there is 
no significant difference between the two averages (58 against 59 years). 
In these cases we have dealt only with completed families and have taken 
every family without selection. If, however, we consider only the cases in which 
