Theories about Physical State of Protoplasm :

1. Alveolar Theory by Butschli in 1892 - Protoplasm consists of bubbles or alveoli of a fluid of lesser density distributed in a fluid of greater density.

2. Granular Theory by Altmann in 1893 - Protoplasm consists of numerous fine granules dispersed uniformly in a homogeneous fluid medium.

3. Fibrillar Theory by Fisher(1894) and Flemming(1897) - This theory states that protoplasm consists of numerous thread-like structure dispersed in fluid medium.

4. Reticular Theory by Hanstein,Klein and Carnoy - Protoplasm consists of numerous minute fibrils which forms a network or reticulum in a fluid medium.

5. Crystallo Colloidal Theory - It was proposed by Fischer, Hardy and Wilson. According to this theory subsatnces are dissolved and dispersed in water forming colloidal as well as true solution.