Immunocompetent cells in avian paraocular glands.

A study was made of the Harderian and lachrymal glands of fowls, pheasants, turkeys and pigeons. Accumulation of heterophils and plasma cells commenced soon after hatching, was well advanced by four weeks of age and was always greater in the Harderian than in the lachrymal glands. Plasmablasts entered via interlobular capillaries, maturing as they migrated to and congregated round the lobular collecting ducts. Their secreted immunoglobulin was readily demonstrated in the duct lumen. Russell body containing cells of diverse morphology were a consistent feature of infiltrated Harderian glands. Though scant in the glands proper, lymphoid tissue was abundant in the walls of their draining ducts.