1. Department of Anatomy; Faculty of Medical Sciences, University of Fukui; Eiheiji Fukui 910-1193 Japan
2. Research and Education Program for Life Science, University of Fukui; Fukui Fukui 910-8507 Japan
3. Laboratory of Veterinary Anatomy, Faculty of Applied Biological Sciences, Gifu University; Yanagido Gifu 501-1193 Japan