174 NATURAL INHERITANCE. [CHAT.
consumptive taint of each fraternity. For instance, if in a fraternity of 10 members there was one actually consumptive member and four "somewhat suspiciously" so, it would count as a fraternity of ten members, of whom two were actually consumptive, and the average taint of the fraternity would be reckoned at one-fifth part of the whole or as 20 per cent.
Treating each fraternity separately in this way, and then averaging the whole of them, the mean taint of the children of one consumptive parent was made out to be 28 per cent.
Distribution of Fraternities.-Next I arranged the fraternities in such way as would show whether, if we reckoned each fraternity as a unit, their respective amounts of consumptive taint were distributed " normally " or not. The results are contained in line A of the following table :
PERCENTAGE OF CASES HAVING VAAIOUS PERCENTAGES OF TAINT.
| |
Percentages of Taint. |
| |
0
and
under
9 |
10
and
under
19 |
20
and
under
29 |
30
and
under
39 |
40
and
above |
total, |
|
A. 66 cases, one
parent con- |
27 |
20 |
9 |
15 |
29 |
100 |
|
sumptive. |
|
|
|
|
|
|
|
B. 84 cases, one |
|
|
|
- |
|
|
|
brother con- |
49 |
14 |
10 |
13 |
14 |
100 |
|
sumptic e. |
|
|
|
|
|
|
