Abstract While conducting a series of experiments with Japanese quail (Coturnix coturnix japonica) from the California random line 908, an adult male was found possessing three testes (Fig. 1). The left testis was normal in size (0.923 gm.). The right testis was divided, the cranial portion being larger (0.344 gm.) than the caudal portion (0.284 gm.). Microscopic examination verified that spermatogenesis was proceeding actively in all three testes. Both the left epididymis and ductus deferens were normal in appearance and disposition. A single epididymis served both divisions of the right testis, and a poorly developed, thread-like ductus deferens passed from the right epididymis toward but not reaching the cloaca. In addition to the anomalous right testis there was also absence of the right kidney and its ureter, which resulted in the left kidney being larger (0.900 gm.) than usual. No other defects were noted. The occurrence of this type of…