The gemmules were supposed to be transported throughout the entire
body, and to congregate in the germ-cells, which in a sense would be
minute editions of the body which bears them, and would then be capable of
producing the same kind of a body. If true, this view would lead to the
acceptance of Lamarck's or even Buffon's doctrine, for changes induced in
any organ by other than congenital factors could be impressed upon the
germ-cell, and would then be transported together with the original
specific characters to future generations. Darwin was indeed a good
Lamarckian.
But the researches of post-Darwinians, and especially those of the
students of cellular phenomena, have demonstrated that such a view has no
real basis in fact. Many naturalists, like Naegeli and Wiesner, were
convinced that there was a specific substance concerned with hereditary
qualities as in a larger way protoplasm is the physical basis of life. It
remained for Weismann to identify this theoretical substance with a
specific part of the cell, namely, the deeply staining substance, or
chromatin, contained in the nucleus of every cell. Bringing together the
accumulating observations of the numerous cytologists of his time, and
utilizing them for the development of his somewhat speculative theories,
Weismann published in 1882 a volume called "The Germ Plasm," which is an
immortal foundation for all later work on inheritance.
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