1. United Graduate School of Veterinary Sciences; Gifu University; Gifu 501-1193 Japan
2. Department of Histology, Faculty of Veterinary Medicine; South Valley University; Qena 83523 Egypt
3. Laboratory of Veterinary Anatomy, School of Veterinary Medicine; Kitasato University; Towada, Aomori 034-8628 Japan
4. Laboratory of Veterinary Anatomy, Faculty of Agriculture; Iwate University; Morioka Iwate 020-8550 Japan
5. Emeritus Professor, Faculty of Agriculture; Iwate University; Morioka Iwate 020-8550 Japan