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The tendency is to assign to these last a life of their own, apart from, and unconnected with that of the other cells of the body, and to cheapen all evidence that tends to prove any response on their part to the past history of the individual, and hence ultimately of the race. Professor Weismann is the foremost exponent of those who take this line.
If you put to the two the time-honored question, Which is first, the owl or the egg? Weismann would announce, with emphasis, The egg; Darwin would say, The owl. One proposition is the converse of the other, and most facts accord almost equally well with both theories.
The active efforts and voluntary disposition of the parents have given an increased predisposition to the child. "Quite the reverse," says Weismann, "the increase of an organ in the course of generations does not depend upon the summation of exercise taken during single lives, but upon the summation of more favorable predispositions in the germ."
A vital conception of Evolution would have taught Weismann that biological problems are not to be solved by assaults on mice. The scientific form of his experiment would have been something like this. First, he should have procured a colony of mice highly susceptible to hypnotic suggestion.
Since his day they have been re-discovered or rather re-named by a host of students, including Haeckel, Weismann, and many of scarcely less distinction. The Mendelian "factors," as I maintain must be clear to any student of the idea, are Spencer's physiological units.
A logical result of the theory is the impossibility of the transmission of acquired characters, since the molecular structure of the germ-plasm is already determined within the embryo; and Weismann holds that there are no facts which really prove that acquired characters can be inherited, although their inheritance has, by most writers, been considered so probable as hardly to stand in need of direct proof.
Panmixia, however, as Weismann has shown, would probably be the most important factor in causing blindness. Darwin says: "A horse is trained to certain paces, and the colt inherits similar consensual movements." But selection of the constitutional tendency to these paces, and imitation of the mother by the colt, may have been the real causes.
Oh, we are very practical, Hester and I. And we are both strong enough to lead each our own lives. Which reminds me that you have not asked about her. First, let me shock you she, too, is a scientist. It was in my undergraduate days that we met, and ere the half-hour struck we were quarrelling felicitously over Weismann and the neo-Darwinians.
There is thus, according to Weismann, nothing to direct variation to certain organs, or to guide and combine the variations of these organs along certain lines, except natural selection. To a certain extent variation may be limited by the very structure of the animal. But within these limits there are wide ranges where one variation is apparently just as likely to occur as another.
He was a scientist, yet he was of a nation that had produced Goethe as well as Weismann and his heart was quick to respond to truth, shot with the rainbow tints of vision. "I know!" he said. "I know! Man needs the impulse of national pride and honor behind his mind. There are those that claim that they achieve for human kind and not for their own race alone. But I doubt it.
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