________________
Hereditary
transmis. sion impossible.
individuals of successive generations. Hence it follows that the transmission of acquired characters is an impossibility, for if the germ-plasm is not formed anew in each individual, but is derived from what preceded it, its structure, and above all, its molecular constitution can not depend upon the individual in which it happens to occur, but such an individual only forms, as it were, the nutritive soil at the expense of which the germ-plasm grows, while the latter possessed its characteristic structure from the beginning, viz., before the commencement of growth. But the tendencies of heredity, of which the germ plasm is the bearer, depend upon this very molecular structure and hence only those characters can be transmitted through successive generations which have been previously inherited, viz., those characters which were potentially contained in the structure of the germ.plasm. It also follows that those other characters which have been acquired by the influence of special, external conditions during the life-time of the parent, cannot be transmitted at all." (vol. I. p. 273-) "But at all events," sums up Dr. Wiesman,
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