The stages of formation, development and involution of the different structural and functional spleenic zones (thymus-dependent and thymus-independent) have been observed in detail for the first time.
The close relation between the different developmental stages of the white pulp of spleen and the level of its hemocirculatory bed was established.
Several developmental periods of the white pulp structure and its hemocirculatory bed, changes of the T-cell population in periarterial lymphoid cuffs and lymph nodes were revealed as a result of the investigation.