476 
Hereditarij Deafness 
TABLE XIII. 
Showing pairs which can he made out of a family of 12 persons, 
6 deaf and 6 hearing. 
Deaf 
Hearing 
Hearing 
Deaf. 
36 
30 
30 
36 
TABLE XIV. 
Showing total number of pairs made out of the 3837 families used. 
Deaf 
Hearing 
Hearing 
Deaf 
23,772 
5226 
88,572 
23,772 
member. They should therefore be compared with hearing people contained in 
families which have at least one married member. If they bear the same 
numerical i-elation to these that deaf people in general do to hearing people in 
general, then they occur in a total number of 5423 multiplied by 1,000,000/659 
persons. Assuming that the mean size of families, which contain a married 
member but do not contain a deaf one, is the same as that of families which 
contain a deaf married one, and that the distribution of size is the same ; then, as 
from 5423 deaf persons 23,772 plus 5226 (equals 28,998) pairs can be made with 
their brothers and sisters, the total number of pairs which can be made from 
X 1,000,000 persons is x 1,000,000 x ^,^^=44,003,035. Deducting 
boy Oo9 o42o 
from this number all the pairs that contain deaf-mutes there are left 43,950,262 
pairs of hearing and hearing brothers and sisters, and by substituting this number 
for the number of pairs of hearing and hearing in Table XIV., Table XV. is 
obtained. 
TABLE XV. 
Fraternal Correlation Table constructed from Table XIV. 
Deaf 
Hearing 
Hearing 
23,772 
43,950,262 
Deaf 
5226 
23,772 
A =■ /I- =3-212070 
H = K^ -002294 
-74 
