Quantitative histological studies on the spleen of ducks after neonatal thymectomy and bursectomy.

The duck spleen was examined histoplanimetrically after neonatal surgical thymectomy, cyclophosphamide treatment, and/or X-ray irradiation. The development of the periarterial lymphoid tissues, which consisted mainly of small lymphocytes, was inhibited in the spleen of the Tx and Tx-X ducks. The peri-ellipsoidal lymphoid tissues, consisting of pyroninophilic medium or large sized lymphocytes, was greatly depleted in the Bx and/or CY ducks. The germinal centres also showed probable bursa dependency. On the other hand, the development of the perivenous lymphoid tissue was not inhibited after Tx and Bx. A number of plasma cells was distributed in the red pulp of the Bx and/or CY duck spleen.