Affiliation: | (1) Zoological Institute, University of Bonn, FRG;(2) Anatomical Institute, University of Essen, FRG;(3) Institute of Organic Chemistry, University of Stuttgart, FRG;(4) Zoologisches und Vergleichend-Anatomisches Institut der Universität Bonn, Poppelsdorfer Schloß, D-5300 Bonn 1, Federal Republic of Germany |