344 
ciated with a pigmentary retinitis and 
choryditis” and ‘this condition,’”’ Dr. 
Penrose assured us, “is one stated by 
the authorities to be due to the effects 
of consanguineous marriage.”’ 
Fortunately, the pedigree was fairly 
full and I was able to carry several lines 
of it through the sixth generation. 
There was, indeed, a_ considerable 
amount of consanguineous marriage 
involved. When I came to measure 
the amount of inbreeding represented by 
these blind boys, I was struck by the 
fact that it is almost identical with the 
amount represented by the present 
Kaiser of Germany.’ 
The coincidence seems to me eloquent. 
I am unable to see in such a history 
as that of Hopetown, Bahama Islands, 
any evidence that consanguineous mar- 
riage necessarily results in degeneracy. 
It seems to me that Dr. Penrose himself 
points to a potent factor when he says 
of his chart, in another connection: 
“Tt will be noticed that only a few of the 
descendants of Widow Malone (the first 
settler at Hopetown) are indicated as 
having married. By this it is not meant 
that the others did not marry; many of 
them did, but they moved away and 
settled elsewhere, and in no way affected 
the future history of the settlement of 
Hopetown.”’ 
I have an idea that, by moving away, 
they did very decidedly affect the future 
history of Hopetown. Who are the 
emigrants’ Inmost cases, probably the 
more enterprising and intelligent, the 
physically and mentally superior of 
the population, who rebelled at the 
limited opportunities of their little 
village, and went to seek a fortune in 
some broader field. The best went; 
the misfits, the defectives, stayed be- 
hind to propagate. Emigration in such 
a case has the same effect as war; it 
drains off the best stock and leaves the 
weaklings to stay home and propagate 
their kind. Under such conditions, 
defectives are bound to multiply, re- 
gardless of whether the marriages are 
consanguineous. 
“Tt will be seen at. a glance,” Dr. 
Penrose writes, ‘‘that early in the history 
2See von Gruber and Ridin, Fortpflanzung, Vererbung, Rassenhygiene, p. 169. 
1911. 
with results for which the 
The Journal of Heredity 
of the Malone family these indications 
of degeneracy were absent; but they 
began in the fourth generation and 
rapidly increased afterward until they 
culminated by the presence of five 
idiots in one family. The original 
stock was apparently excellent, but the 
present state of the descendants is 
deplorable.”’ 
Now three generations of emigration 
from a little community which even 
today has only 1,000 inhabitants, would 
naturally make quite a difference in the 
average quality of the population, 
eugenically speaking. In almost any 
population, a few defectives are con- 
stantly being produced. Take out the 
better individuals, and leave these 
defectives to multiply, and the amount 
of degeneracy in the population will 
increase, regardless of whether the de- 
fectives are marrying their cousins, or 
unrelated persons. The family of five 
idiots, cited by Penrose, is an excellent 
illustration, for it is not the result of 
consanguineous marriage—at least, not 
in a close enough degree to have ap- 
peared on the chart. It zs doubtless a 
mating of like with like; and biologically 
that is all that consanguineous marriage 
is. Only, if two people are related by 
blood, they are more likely to carry the 
same hereditary traits than are two 
strangers. This is by no means always 
the case: if two inmates of an institu- 
tion for the deaf, or the feeble-minded, 
or the epileptic, marry (they are doing 
it frequently, in most parts of the 
United States) it is perfectly obvious 
that they probably have the same in- 
herited defect; while the chance that 
children with one of these defects would 
result from the marriages of first 
cousins, in whose family the defect was 
not previously known, is practically nil. 
Honesty demands, therefore, that 
consanguineous marriage be not credited 
consan- 
guineous element is in no wise respons- 
ible; and the prevailing habit of picking 
out a community or a strain where con- 
sanguineous marriage and defects are 
associated and loudly declaring the one 
to be the cause of the other, is a perni- 
Munchen, 
