[289]. I have used the expression ‘transient’ (‘passant’) in the same sense as ‘acquired,’ in order to enforce the conclusion that they are merely temporary, and disappear with the individual in which they arise. Since the characters of which Hoffmann speaks are hereditary, the term cannot be rightly applied to them, and I shall prove later on that they cannot be regarded as acquired characters in the sense required by the theory of descent.
[290]. Compare a paper by J. Orth, ‘Ueber die Entstehung und Vererbung individueller Eigenschaften,’ Leipzig, 1887. This author considers my theory of the non-transmission of acquired characters to be incorrect, because he will insist upon using the term ‘acquired’ for those characters which are due to spontaneous changes in the germ; although he considers that they are only indirectly acquired. He also reproaches me with not having discriminated with sufficient clearness between the two modes in which new characters are acquired by the body, and with having altogether failed to take into account the class of characters which are due to variations in the germ. On the very same page he quotes the following sentence from my writings:—‘Every change of the germ-plasm itself, however it may have arisen, must be transmitted to the following generation by the continuity of the germ-plasm; and hence also any changes in the soma which arise from the germ-plasm must be transmitted to the following generation.’ Not only does the transmission of Orth’s ‘indirectly acquired characters’ necessarily follow from this sentence, but it is even distinctly asserted by it. I cannot understand how any one who is aware of what happened at the meeting of the Association of German naturalists at Strassburg in 1885, can charge me with the confusion of ideas which has prevailed since Virchow took part in the discussion of this question.
[291]. His, ‘Unsere Körperform,’ Leipzig, 1874, p. 58.
[292]. Compare on this point Nägeli in his ‘Theorie der Abstammungslehre.’ This writer also concludes from similar facts that external influences have wrought in the idioplasm, changes which were at first ineffectual, and which only increased during the course of generations up to a point at which they could produce visible changes in the plant. He does not, however, draw the further conclusion that these changes only influence the germ-plasm, for he was not aware of the distinction between germ-plasm and somatoplasm.
THE SUPPOSED TRANSMISSION OF
MUTILATIONS.
1888.
A lecture delivered at the Meeting of the Association of