inherited tuberculosis from two uncles who died of
consumption. For years I had known that I was a marked victim. Silently
I carried my tragedy, suspecting each cold and headache to be the
telltale messenger that should let others into my secret. He was a
veritable emancipator who informed me that heredity did not work from
uncle to nephew; that not more than a predisposition to consumption
could pass even from parent to child; that a predisposition to
consumption would come to nothing without the germ of the disease and
the environmental conditions which favor its development; and that if
those so predisposed avoid gross infection, lead a healthy life, and
breathe fresh air they are as safe as though no tuberculous lungs had
ever existed in the world. Some years later I learned to understand the
other side of the case; I realized how I had been in real danger of
contracting consumption in the darkened, ill-ventilated sick room of
the uncle who taught me my letters and gave me my ideal of God's
purpose in sending uncles to small boys.

There are two distinct things which make each individual life: the
living stuff, the physical basis of life, handed down from parent to
child; and the environmental conditions which surround it and play upon
it and rouse its reactions and its latent possibilities. It is like the
seed and the cultivation. You cannot grow corn from wheat, but you can
grow the best wheat, or you may let your crop fail through careless
handling.

It is well that we should think seriously about the part played by
heredity, for the living stuff of the future depends upon our sense of
responsibility in this regard. The intelligent citizen would do well to
read such a book as J. Arthur Thompson's _Heredity_ (1908), in which
the latest conclusions of science are clearly and soundly set forth.

The main problem of to-day, however, is to use well the talents that we
have. Here two things should always be kept in mind: First, the
inherited elements which make up our minds and bodies are complex and
diverse. Health and strength are inherited as well as disease and
weakness; they have indeed a better chance of survival. In the most
unpromising ancestry there are latent potentialities which may be made
fruitful by effort. No limit whatever can be set to the possibilities
of improvement in any individual.

In the second place, if science has shown anything more clearly than
the importance of heredity, it is the impo