The laws of heredity : their definite meaning and interpretation / editor: Henry Smith Williams, M.D., LL.D.

Date:
[1914]
Catalogue details

Licence: Public Domain Mark

Credit: The laws of heredity : their definite meaning and interpretation / editor: Henry Smith Williams, M.D., LL.D. Source: Wellcome Collection.

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    course, passed on to the descendants of the bac- terium, inasmuch as these descendants constitute, essentially, portions of the parent form. Exactly the same thing applies to the allied process of reproduction of the germ-plasm cells of the higher organism. Modified conditions of en- vironment — changed conditions of temperature and of nutrition — may in some cases modify them, and such modifications will be transmitted to their offspring. It is obvious that if such were not the case there could be no change in the structure or con- stitution of any given line of organisms from the remotest ancestor to the most recent descendant; inasmuch as the hereditary and permanent altera- tions of the body-plasm are contingent — accord- ing to hypothesis — upon modifications of the germ-plasm. But as nowadays it is fully admitted that all forms of life have undergone change in the past — higher forms evolving from lower ones through modification — it is obvious that each stream of ancestral germ-plasm must have been more or less subject to influences that modify it. As much as this at least is admitted by every biologist, whatever his view toward the allied question of the heritability of modifications that effect the body-plasm of an individual rather than [6]
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