to make more definite statements, we no doubt shall
find that heredity is the most important single factor in the
disgraceful prevalence of crime, disease, and defect in our
communities: indeed this is practically demonstrated to-day. These are
questions of the most fundamental importance in our national
life-history: our only "hope of perpetuity" lies in the right solution
of such problems. And the crying need is for facts, always more facts.

The Galton Laboratory for Eugenics is already doing much in this
direction and is publishing in the "Treasury of Human Inheritance"
scores of human pedigrees. An agency is already in operation in this
country. The American Breeders Association has appointed a Committee
and Sub-Committees under highly competent leaders for the collection
of exact data of human heredity upon a large scale. There is
opportunity for everyone to help in this work in connection with the
Eugenics Record Office already referred to.

The second great element in the eugenic program is Research. It is not
enough to collect the known facts; new facts must be forthcoming. We
cannot, perhaps, undertake definite experiments upon human evolution,
but we can and must take advantage of the wealth of experiment which
Nature is carrying out around us and before our eyes could we but
learn to read her results. We need to know more about the process of
differential fertility, of human variability, of the effects of
Nurture as well as of the conditions of Nature.

We do know pretty well the effects, upon the individual, of training,
education, good and ill housing conditions and conditions of labor, of
disease, alcoholism, underfeeding. We need now to know, not to guess
at, the effects of these things upon the race, upon human stock. A
mere beginning has been made here in the way of a scientific treatment
of this question, although many persons have their minds already made
up, firmly and fully, as to the "effects of the environment." But all
that we have guessed here may be wrong.

The discussion of this subject is filled with pitfalls. The common
form of the query as to which is of the greater importance, "heredity
or environment," in determining individual characteristics betrays a
completely erroneous view of what heredity is, and of the organism's
relation to its environment. The living organism reacts to its
environment at every stage of its existence, whether as an egg, an
embryo, or an adult. In this reacti