er of deep concern,
though the hazard is materially larger than for adventitious deafness.
When there are deaf relatives involved, the peril, made stronger if
coupled with congenital deafness, is most pronounced; and, indeed, the
existence of collateral deafness seems a more certain sign of warning
than direct heredity itself. Finally, even in the marriage of the deaf
with the hearing, the dangers are not in fact lessened if conditions
otherwise unchanged are attendant.

What action should be taken in respect to that part of the deaf who may
marry under conditions favorable to the production of deaf offspring is
not at present clear. Legislation would not appear on the whole to be
advisable;[58] and the exertion of moral suasion, so far as possible, in
the individual cases concerned would seem a more acceptable course. The
matter, however, really belongs in the province of eugenics, and we will
probably do best to await the authoritative pronouncement of its
decrees before full procedure is resolved upon.

CONGENITAL DEAFNESS AS AN INCREASING OR DECREASING PHENOMENON

The final matter to be ascertained in respect to congenital deafness is
whether it is relatively increasing or decreasing. The following table
will show the number of the congenitally deaf in the censuses of 1880,
1890, and 1900, with their respective percentages and the ratios per
million of population.[59]

NUMBER OF THE CONGENITALLY DEAF IN 1880, 1890, AND 1900

RATIO PER
TOTAL CONGENITALLY PER MILLION OF
NUMBER DEAF CENT POPULATION

1880 33,878 12,155 35.6 242
1890 40,562 16,866 41.2 269
1900 37,426 12,609 33.7 166

From this it appears that congenital deafness is decreasing both in
relation to all deafness, and to the general population.

For further statistics, we may revert to our tables under adventitious
deafness. In the tables relating to periods of successive recent years
we find in respect to three schools, the New York and Western
Pennsylvania institutions and the Maryland School, with certain
fluctuations, no great change on the whole, though the last named school
shows still a very high proportion. In two schools, the Michigan and
Wisconsin, rather an increase is observed. In the Pennsylvania
Institution, which covers a period of seventy