478 
Hereditary Deafness 
TABLE XVII. 
Allowing total number of deaf persons in families containing at least one co)i- 
genitally deaf person, also in those containing at least one person tvlio has 
acquired deafness. 
Number 
Nature of Deafness 
of Deaf 
Totals 
Persons in 
TVq vn 1 1 T7 
Congenital 
Acquired 
Doubtful 
1 
524 
2260 
101 
2885 
2 
354 
221 
22 
559 
8 
189 
73 
13 
242 
Jf 
82 
22 
5 
99 
5 
25 
4 
4 
31 
6 
8 
1 
9 
7 
8 
1 
1 
9 
8 
1 
1 
1 
9 
2 
2 
Totals 
1193 
2583 
146 
3837 
N.B. 85 families are included both in the congenital and in the acquired class, as they 
contain at least one member in each of these two classes. 
Gonclusio7is. 
In conclusion it need hardly be pointed out that the results obtained can only 
be regarded as provisional, as the data on which they are based were not collected 
with a view to the construction of correlation tables, and are therefore not 
particularly well suited to this purpose. 
With this reservation it may, however, be asserted that striking confirmation 
has been obtained of previous work on widely different characters, at any rate 
with regard to the correlation between father and children, and mother and 
children. 
Quite recently our knowledge of this subject has been greatly enlarged and 
lucidly summarized by Prof. Pearson and Dr Lee in their paper, " On the Laws 
of Inheritance in Man " (Biometrika, Vol. ii. p. 355) ; and it will be unnecessary 
to repeat here the excellent comparative tables that are given there. It will be 
sufficient to mention one or two examples to show for what a broad range of 
characters parental inheritance has been measured, and to quote the general 
conclusion of the authors on this point. 
While it has been found in the present paper that the mean of the results 
obtained by four different methods for the inheritance of deafness is '54 for fathers 
and children and "535 for mothers and children (vide Table XL), the mean value 
of parental inheritance of stature in man is '506, of span, "459, and of eye colour, 
■495 ; similarly that of coat-colour in horses is '522, in Basset hounds '524, and in 
