[Age and thymus morphology of pavian hamadrils]

By different histological methods, 23 thymi have been studied in Papio hamadryas of 5 age groups: fetuses, newborn, one-year-old, mature and old animals. By morphometric methods percentage of quantitative relations of the cortical and medullary substances, as well as their cell composition have been estimated. A rather great similarity in morphogenesis and age histology has been noted in human and monkey thymus. The character of histochemical reactions in thymus corpusculi supports the view on participation of some epithelial structures in the organ's functional activity. Similar supposition is made on the thymus cystic formations.