Lymphocyte: erythrocyte (L.E.) rosettes as indicators of the heterogeneity of lymphocytes in a variety of mammalian species.

Lymphocytes and red cells from various mammalian species have been mixed in vitro in conditions which favor their aggregation in the form of rosettes. The frequencies of rosette formation taken in conjunction with observations on surface bound immunoglobulin on the lymphocytes favor the interpretation that, in many species of animal, rosette formation can be used as an indicator of the thymic (T) or bursal equivalent (B) origin of lymphocytes.