[Cytoarchitectonics of different areas of the thymus in rats]

Correlation of various parts in the gland of white non-inbred 3-month-old male rats has been studied morphometrically. Five zones have been distinguished in the lobe: in the cortex--subcapsular, middle and border-like with medullary substance, in the medulla--border-like with cortical substance, deep zones. A high level of dividing and capable for division poorly differentiated cell forms, especially in the thymic cortex are noted in the gland's contents.