76 The Journal 
any injuries result they are not so great 
but that they can be counteracted by 
careful selection of the animals used. 
And after all, does the practical live- 
stock breeder need to know any more 
than that? For the sake of clearing up 
theoretical views on the subject, it would 
be highly desirable to get evidence that 
inbreeding is or is not injurious in itself, 
wholly without regard to selection; but 
such can hardly be had from experiment. 
And as every breeder, under ordinary 
circumstances, is selecting from his stock 
all the time, it is sufficient for him, if he 
is told that by careful enough selection 
all evil effects have been avoided, and 
good results gained in an experiment 
with rats, in which they were closely in- 
bred for a much longer time than would 
ever be used in the commercial produc- 
tion of livestock. 
But no one experiment will settle the 
general problem of inbreeding. What 
takes place in rats might or might not be 
expected to take place in swine; at any 
rate the Delaware station could not 
make it take place. And no breeder 
could be advised to inbreed cattle for 
of Heredity 
twenty-one generations, even with the 
most rigid selection, and not expect 
trouble, merely because rats have been 
successfully inbred for that length of 
time. 
Great progress has been made during 
the last generation in solving the prob- 
lem of inbreeding, but the final solution 
has by no means been reached. It can 
hardly be reached until we know ex- 
actly what inbreeding means physiolog- 
ically; and in this field we are at present 
largely dependent on hypothesis. 
The results of Dr. King’s experiment 
in breeding rats, and the whole teaching 
of genetics, however, can be safely fol- 
lowed by the practical breeder to this 
extent: that he can use a moderate de- 
gree of inbreeding through a number of 
generations without fear of evil results, 
provided he ts mating the best with the best 
in each generation; and that the results 
in most cases will be a considerable im- 
provement in his stock.4 The super- 
stitious fear of inbreeding in any form, 
which long hung over practical breeders, 
is rapidly disappearing; for the geneticist 
it long ago ceased to exist. 
4 Much of the improvement in German livestock during the last generation is due to the 
moderate practice of inbreeding on the advice of geneticists, according to Dr. Georg Wilsdorf. 
See his discussion of the subject in ‘“‘German Zootechny,’’ JOURNAL OF HEReEpITy, March, 1915, 
Vol. VI, No. 3, p. 109. 
Annual Business Meeting of the Association 
At the annual business meeting of the American Genetic Association, held in 
Washington on January 13, it was decided to hold the next general meeting in con- 
nection with the American Association for the Advancement of Science in New 
York, December 26 to December 31,1916. O. F. Cook, David Fairchild and Arthur 
W. Gilbert, whose incomplete term of two years as members of the council expired, 
were elected to succeed themselves. The secretary’s report showed the membership 
of the Association to be 2,722. 
Annual Meeting of the Council 
The annual meeting of the council of the American Genetic Association was 
held in Washington on January 18. The present officers were re-elected. Mr. 
Kearney was elected a member of the executive committee, to act with the president 
and secretary. Plans were considered for securing advertising for the JOURNAL. 
