The evidence of related immune cells implied that emergence time of acquired immunity cells is later than natural immunity cells in the lymphoid tissues of sacculusrotundus, and that the sacculus rotundus are peripheral immune organ.

• 从免疫相关细胞成分来看,巨噬细胞和NK细胞在兔出生当日就有,而T细胞、B细胞则在5天以后才出现。 这说明兔圆小囊淋巴组织中获得性免疫细胞的发育较天然免疫细胞的发育明显迟后,同时也表明圆小囊是一个外周免疫器官。