1. Department of Invertebrate Zoology and Parasitology; University of Gdańsk; Wita Stwosza 59 Gdańsk 80-308 Poland
2. Laboratory of Electron Microscopy; University of Gdańsk; Wita Stwosza 59 Gdańsk 80-308 Poland
3. Department of Plant Cytology and Embryology; University of Gdańsk; Wita Stwosza 59 Gdańsk 80-308 Poland