Relationships between specialized cells, capillaries, and intermediary cyto-fibrillar elements. Vth note. Organizational steps or levels of these relationships during their biological development.

The developmental analysis of the interrelations between specialized cells, capillaries, and intermediary cyto-fibrillar elements points out the existence of four organizational steps reflecting the gradual increase in complexity and diversity of animal structures and functions. The development of secretory and defence functions produces a dissociation of steps between the increase of the organizational level of the whole animal organism and the autonomy of organizational steps or organs. The steps are not immovable, but under some conditions the possibility of a mutation exists between the IInd and the IIIrd steps.