Hello!!

Theory of inheritance of acquired character was the theme of his theory.

As you have asked about the salient feature it was-

Every organism is having the internal vital force due to this force the size of the organs and it's organ increased.

Doctrine of perfection-every organism adjust to the changing environment perfectly.

New need-enviroment does not remain constant it keeps changing in  the changed environment new need develops.

Doctrine of Appetancy-It is the wish of the organism to modify itself according to the changed environment.

Use and disuse- In the changed environment some body parts are used more it becomes gradually well developed and the body parts that is less used become weaker.

Transfer of acquired character-the character which develops in the life time is transferred to the next generation.