an in vitro culture system for embryonic chicken bursa is described , in which development , as measured by follicle formation ( site of b lymphocyte development ) , position of large basophilic cells ( stem cells ) , and presence of lymphocytes and cells containing cytoplasmic immunoglobulin ( b cells ) , was comparable to that of the bursa in vivo .
C1511002
b lymphocyte
C0004561
b cells