Art said -
a boy child is given his maternal grandfather's surname as a middle name

Moving from US to Australia - in the 1920's my father was given his mother's surname as his middle name & his grandson (son's son) was also given this same middle name in the 1990s. I don't know if this was a widespread habit in the 20s, but I'm not aware of anyone doing the same in the late 20th century.

sandra