all other cases of telegony which can not be explained, as in most instances they can be, by the mixed ancestry of the offspring and the innate tendency of all living things to vary.
Now to sum up this long chapter. We started with a consideration of the germ-plasm, the physical basis of life; pointing out that it is continuous from generation to generation, and potentially immortal; that it is carefully isolated and guarded in the body, so that it is not likely to be injured by any ordinary means.
One of the logical results of this continuity of the germ-plasm is that modifications of the body of the parent, or acquired characters, can hardly be transferred to the germ-plasm and become a part of the inheritance. Further the experimental evidence upholds this position, and the inheritance of acquired body characters may be disregarded by eugenics, which is therefore obliged to concern itself solely with the material already in existence in the germ-plasm, except as that material may be changed by variation which can neither be predicted nor controlled.
The evidence that the germ-plasm can be permanently modified does not warrant the belief; and such results, if they exist at all, are not large enough or uniform enough to concern the eugenist.
Pre-natal culture and telegony were found to be mere delusions. There is no justification for hoping to influence the race for good through the action of any kind of external influences; and there is not much danger of influencing it for ill through these external influences. The situation must be faced squarely then: if the race is to be improved, it must be by the use of the material already in existence; by endeavor to change the birth-and death-rates so as to alter the relative proportions of the amounts of good and bad germ-plasm in the race. This is the only road by which the goal of eugenics can be reached.