(a) Schematic outlines of the experimental approaches tested in geese; (b) Effects of PAMK on histology, ultramicroscopic morphology of geese thymus treated with CTX. A. HE staining of the thymus (400 × ); B. Scanning electron microscopy (SEM; 3000 × ) of the thymus. C. Transmission electron microscopy (TEM; 3000 × ) of the thymus. ★ indicates cortical, ▲ indicates medullary, the red arrow points to normal lymphocytes, the black arrow points to wrinkled lymphocytes, the yellow arrow points to apoptotic lymphocytes, the orange arrow points to connective tissue, the blue arrow points to red blood cells.