The Action of Hanson’s Thymus Extract on the Mouse

Hanson's study on the effects of thymus gland extracts in albino rats demonstrated significant acceleration in growth and morphological differentiation. Over four generations, rats injected with the extract from the 16th day of life showed earlier development of hair, teeth, and sexual maturation compared to controls. Notably, the F2 generation exhibited the most pronounced effects, with continued enhancement in subsequent generations. For instance, the average time for vaginal opening decreased from 60-70 days in controls to 18-19 days in the F4 generation, and hair appearance advanced from 14-17 days to just 3 days.