Late fetal and postnatal formation of the thymic medulla.
D000818:Animals; D001344:Autopsy; D002454:Cell Differentiation; D002465:Cell Movement; D002675:Child, Preschool; D005260:Female; D006168:Guinea Pigs; D006801:Humans; D008297:Male; D011817:Rabbits; D013950:Thymus Gland / Q000166:cytology / Q000196:embryology* / Q000254:growth & development*