The development of lymphatic follicles in the omentum after intraperitoneal stimulation of rats.

China ink and typhoid vaccine were used as peritoneal stimuli injected in single doses. The subsequent omental reaction was studied after several time intervals: 6 and 12 hours, 1, 2, 3, 4 and 8 days, 3 and 6 weeks. The omental reaction featured as lymphatic nodules connected to milky spots was compared with a primary immune response. The ultrastructure and development of the characteristic cells (lymphocytes, lymphoblasts, dendritic reticulum cells, tingible body macrophages and plasma cells) was investigated throughout the period from 6 h to 6 weeks. A special attention was devoted to ultrastructural and functional features of plasma cells.