I] Protoplasm as a colloidal system:
Basically the hyaloplasm or cytoplasm is a complex colloidal system. Its colloidal structure was suggested by Fisher in 1894 and Hardy in 1899. It consists of high water contents containing various solutes of biological importance such as glucose, fatty acids, amino acids, minerals, vitamins, hormones and enzymes.
These solutes may be either soluble in water making it a homogeneous mass or insoluble in it, thus making it a heterogeneous mass. This suspension of particles in the protoplasm is the basis for its colloidal nature. The various components give the appearance to protoplasm of four different kinds: