of heredity." Whatever wisdom, material gain, or language is acquired by one generation may be passed on to the next. As far as the environment is concerned, one generation stands on the shoulders of its predecessor. It might simplify the task of eugenics if the same could be said of biological heredity. But it can not. Each generation must "start from scratch."
In August Weismann's words, the development of a function in offspring begins at the point where it began in his parents, not at the point where it ended in them. Biological improvement of the race (and such improvement greatly fosters all other kinds) must be made through a selective birth-rate. There is no short-cut by way of euthenics, merely.
We must now consider whether there is any direct way of impairing good heredity. It is currently believed that there are certain substances, popularly known as "racial-poisons," which are capable of affecting the germ-plasm adversely and permanently in spite of its isolation and protection. For example, the literature of alcoholism, and much of the literature of eugenics, abounds with statements to the effect that alcohol originates degeneracy in the human race.
The proof or disproof of this proposition must depend in the last analysis on direct observation and carefully controlled experiments. As the latter cannot be made feasibly on man, a number of students have taken up the problem by using small animals which are easily handled in laboratories. Many of these experiments are so imperfect in method that, when carefully examined, they are found to possess little or no value as evidence on the point here discussed.
Hodge, Mairet and Combemale, for example, have published data which convinced them that the germ-plasm of dogs was injured by the administration of alcohol. The test was the quality of offspring directly produced by the intoxicated animals under experiment. But the number of dogs used was too small to be conclusive, and there was