Renal agenesis in guinea pig and oppossum.

Complete absence of kidneys was observed in 3 neonatal guinea pigs which died 2-3 da after birth. Congestion of intestines and other organs was also observed. Renal agencies in the guinea pigs appeared to be of rare occurrence. Agenesis of right kidney was observed in 2 of over 500 opossums examined. Both opossums were males, and the corresponding ureters were smaller in diameter than the contralateral ureters. The left kidney was enlarged as a result of compensatory hypertrophy. The lumina of right ureters were found to be obliterated on microscopic examination.