Figure 1: Histological changes in testes of different treatment groups. Group I animals showed round or oval STs with the epithelium containing Sertoli cells (S) and germ cells of various stages covering the complete spermatogenesis. The BL was thick showing closer association with SG and Sertoli cells. Structures of SG were oval in shape, resting on the basement membrane. Both Type A (SG[A]) and Type B (SG[B]) SG were distinguished in pattern. Sertoli cell cytoplasm showed closer association with germ cells and the elongated spermatids (SD), and the lumen contained mature spermatozoa. CT. In Group II and III animals, most of the damages in testis occurred at the 90^th and 180^th days of administration of Butea monosperma flower extracts. Testicular histology showed round or oval STs with the IE containing DSCs and germ cells. Lack of and disorientation of Type A and B SG indicative of incomplete spermatogenesis. The dilated basal lamina (DBL) showing clear disassociation with SG and Sertoli cells. Spermatids appeared to have disassociated from Sertoli cells, amount of sperm present in the lumen of STs lowered extensively. In addition, Leydig cells appeared UL, showing inconspicuous nuclear and cytoplasmic vacuolization (V) characteristics. The amount of damages was higher in Group IIIb (90 days) and IIIc (180 days) animals comparing to other groups. Following withdrawal from treatment, histological architecture resumed back to normal. Nonetheless, the lumens of STs were still partially filled. ST: Seminiferous tubule, BL: Basal lamina, SG: Spermatogonia, CT: Connective tissue, DSC: disoriented Sertoli cell, UL: Unavailable Leydig cells, V: Vacuolization, IE: Irregular epithelium