Bird, Christopher and Peter Tompkins, The Secret Life of Plants, page 317:
“At the University of Heidelberg’s medical school, from which he was
to receive top honors and the gold medal, Abrams met a Professor de
Sauer, who was engaged—many years before Gurwitsch had happened
on “mitogenetic radiation”—in a bizarre series of experiments with
plants. De Sauer told Abrams that, while transplanting onion seedlings,
he had inadvertently left some of the uprooted onions next to those still
growing in one of several flats. Two days later he noticed that the
seedlings growing on the side of the flat next to the dying plants were
different in appearance from those on the opposite side, De Sauer could
not explain the reason for the difference but Abrams was convinced that
the onion roots were emitting some strange form of radiation and linked
this in his mind with the resonance phenomenon behind Caruso’s voice-
shattered glass.”