He has alopecia on his chin.
same reason he never showed his **** or balls under that loin cloth
one of the Gorilla who was barber did to him.
The bigger question is How come Tarzan wasn't a virgin when he met Jane.
Jane didn't like it
A lot of Native people don't grow facial hair.
but he wasn't native
He wasn't? Then I dunno.
but he wasn't a native...remember, he was orphaned from a plane crash from England