Gustav Gassner
... that the German plant physiologist Gustav Gassner, whose 1931 book remains a popular reference, studied smut?
... that the German <a href="./Plant_physiology" id="mwFGA" rel="mw:WikiLink" title="Plant physiology">plant physiologist</a> <b id="mwFGE"><a href="./Gustav_Gassner" id="mwFGI" rel="mw:WikiLink" title="Gustav Gassner">Gustav Gassner</a></b>, whose 1931 book remains a popular reference, studied <a href="./Smut_(fungus)" id="mwFGM" rel="mw:WikiLink" title="Smut (fungus)">smut</a>?