Note 31 — Chapter II · Characters As Hereditary and Acquired (Preliminary).

I say "the followers of Weismann," because Weismann himself, with his clear perception of the requirements of experimental research, expressly states the above considerations, with the conclusions to which they lead. Nevertheless, he is not consistent in his utterances upon this matter; for he frequently expresses himself to the effect, "that the onus probandi rests with my opponents, and therefore they ought to bring forward actual proofs" (Essays, i. p. 390). But, as above shown, the onus rests as much with him as with his opponents; while, even if his opponents are right, he elsewhere recognizes that they can bring "actual proofs" of the fact only as a result of experiments which must take many years to perform.