Inheritance of acquired characteristics

…Because his eyesight had deteriorated from straining his eyes in his microscopic research, he devoted the latter half of his life to theory, which bore fruit in 1892 with the publication of Das Keimplasma. According to this theory, only the nuclei of germ cells retain all the determining factors for traits, but in somatic cells, determining factors are distributed unevenly as development progresses, and tissue differentiation ultimately occurs under the control of a small number of determining factors, completely denying the inheritance of acquired traits. Weismann's theory was what could be called a modern preformation theory, but it was more sophisticated than other theories and corresponded well to the behavior of chromosomes, which was attracting attention at the time, so it was widely accepted. …

*Some of the terminology explanations that refer to "inheritance of acquired characteristics" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…顕微鏡研究で目を酷使し視力が衰えたため後半生は理論面に力を注ぎ，1892年の《生殖質説Das Keimplasma》として結実した。これによると，生殖細胞の核だけはすべての形質の決定因子を保持し続けるが，体細胞は発生の経過とともに決定因子が不均等に分配されてゆき，最終的に少数の決定因子の支配によって組織分化が起こるとされ，獲得形質の遺伝は全面的に否定された。ワイスマン学説は近代的前成説と呼ぶべきものであったが，他の学説よりも精緻（せいち）で，かつ当時注目されていた染色体のふるまいともうまく対応したため，広く受け入れられた。…

※「獲得形質の遺伝」について言及している用語解説の一部を掲載しています。

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