The three-dimensional organization and anastomoses of lymphatics in the rabbit stomach were demonstrated by scanning electron microscopy of lymphatic corrosion casts. Casting medium is the diluted low viscosity Mercox used for intraparenchymatous injection into the mucosal, submucosal, muscular and serous layers of the stomach. The lymphatic capillaries with blind ends were found in the deep mucosa and the lymphatic capillary networks and lymphatic plexus were observed in all the submucosal, muscular and serous layers. The distinct imprints which correspond to the bicuspid valves of lymphatics and the oval or fusiform impressions of the endothelial nuclei were seen on the casts.

By using 5'-nucleotidase-alkaline phosphatase (5'-Nase-AlPase) double staining method, the fine distribution of the lymph vessels in the stomach wall of the rabbit, guinea pig and rat has been observed. Under light microscope lymph capillaries showed strongly 5'-Nase positive reaction with brown or dark brown staining. However blood capillaries revealed significantly A1Pase activity with blue staining. The lymph capillaries were seen in all layers of the stomach wall in three species, but the lymph vessels were only shown in the submucosa, muscularis and serosa. In the mucosa lymph capillaries could be found in the deep layer of the lamina propria. In the submucosa there were lymph vessels and capillaries. In the muscularis lymph capillaries and vessels not only could be found between oblique and circular muscle or between circular and longitudinal muscle, but also among muscle fiber bundles of each layer. In the serosa there were larger lymph vessels situated near the muscularis. The observation on semithin and ultrathin sections also shown the similarity in the lymph vessels distribution. There was no difference in the distribution of lymph vessels in the stomach wall between rabbit, guinea pig and rat.