The objectives of this contract are to maintain a colony of Rhesus monkeys to achieve self-sufficiency in the supply of very high quality non-human primates to NICHD grantees. The colony is to supply time-mated pregnant females, random-mated pregnant females, embryonic and fetal material, neonates of known gestation, juveniles of known age, and certain biopsy materials, tissues, and fluids. This colony is a reliable source of monkeys and through this contract the aim is to provide excellent service in the delivery to the various research laboratories at scheduled times.