Shigehiko Uni
Isao Kimata
Motohiro Iseki
Department of Medical Zoology, Osaka City University Medical School, Abeno-ku, Osaka 545, Japan.

Yoshitake Suzuki
Laboratory of Veterinary Anatomy, Division of Veterinary Medicine, Faculty of Agriculture, Gifu Unversity, Gifu 501-11, Japan.

Masashi Harada
Laboratiry of Experimental Animals, Osaka City University Medical School, Abeno-ku, Osaka 545, Japan.