from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The theory that all heritable characteristics arise in the germ plasm and that acquired characteristics cannot be inherited.
from the GNU version of the Collaborative International Dictionary of English
- n. The theories and teachings in regard to heredity propounded by the German biologist August Weismann, esp. in regard to germ plasm as the basis of heredity and the impossibility of transmitting acquired characteristics; -- often called neo-Darwinism.
from The Century Dictionary and Cyclopedia
- n. The opinions and teachings of August Weismann, a noted German zoölogist and writer on speculative biology.
- n. In popular biological literature, the doctrine or opinion that acquired characters are not, and can not be, inherited. See doctrine of germ-plasm, substance of heredity, acquired character.
This may be in a physical sense: Weismannism assumes that intergenerational continuity exists only for germ cell nuclei whereas somatic cells and germ cell cytoplasm arise anew in each generation.
Fortuitously initiated development is a condition sine qua non of Darwinism and Weismannism.
Weismannism not only retained the principle of utility and selection, but made it the only principle, rejecting entirely the action of external conditions as a cause of congenital modifications, _i. e._ of characters whose development is predetermined in the fertilised ovum.
Weismannism that not only sex but all other congenital characters are determined in the fertilised ovum or zygote.
Weismannism_ -- occupied a distinguished place in contemporary biology.
Of the English, Herbert Spencer, who however, was averse to the vitalistic attitude, Vines and Henslow among botanists, Cunningham among zoologists, have always resisted Weismannism; but, I think, none of these was distinctly influenced by Hering and Butler.
Weismannism, therefore, is the inevitable outcome of the straits to which Charles-Darwinians were reduced through the way in which their leader had halted between two opinions.
Now let me return to the recent division of biological opinion into two main streams -- Lamarckism and Weismannism Both Lamarckians and
The former is sometimes called the theological view, because it recognises the presence in organic nature of design, whether it be called creative power, directive force, directivity, or vital principle; the latter view, in which the existence of design is absolutely negatived, is now usually described as Weismannism, from the name of the writer who has been its principal advocate in recent years.
Mr. Wallace, therefore, may well be excused if he casts longing eyes towards Weismannism.