in spite of the absence of circulating antibodies or immunoglobulins and of extrinsic antigen in the immunologically virgin sheep fetus , the circulation of lymphocytes through the spleen and lymph nodes of fetal lambs was more intense than in the adult , indicating that the pathways of recirculation and the capacity of cells to recirculate arise as a physiological process independently of antigenic stimulation .
C0003241
antibodies
C0021027
immunoglobulins