THEORY OF GERMPLASM -
- August Weismann (1834-1914) criticized the inheritance of acquired characters by putting forward the theory of continuity of germplasm.
- According to this theory, the characters of influencing the germ cells are only inherited.
- There is a continuity of germplasm (protoplasm of germ cells) is not transmitted to the next generation hence it does not carry characters to next generation.
- Weismann disproved the inheritance of acquired characters by cutting off the tails of rats for about 20 generations and allowed them to breed but tailless rats were never born.
- Weismann stated that organisms comprises of two types of protoplasm - the germplasm, the protoplasm present in germ cells only and which is passed on to the offsprings, and the somatoplasm, the protoplasm forming remain of the body part and plays no role in heredity.
- Darlington commented - "Lamarck's theory is an evergreen superstition".
EXAMPLES AGAINST THE THEORY -
- Muscles of arms and shoulder in blacksmiths.
- Circumcison of foreskin of penis in jews and muslims.
- Piercing of ear -lobe in Indian women.
- Shaving of beard in man.
- The wrestler's powerful muscles are not transmitted to the offsprings.
- Chinese women used to wear iron shoes in order to have small feet, but their children at the time of birth always normal feet.