His mother died in 1943 and his father was murdered in Auschwitz.
Professor Proskauer's thesis research was concerned with the biology and morphology of the British species of the hornwort Anthoceros.
Much of his life's work focussed on this group, and in 1951, he recognized and defined the genus Phaeoceros for the first time.
He continued to work at Berkeley on the morphology and cytology on the hornworts and also the liverworts.
He died in 1970, leaving a legacy of careful and meticulous study.