Abstract: A nursing bottle nipple provides controlled and limited liquid flow by providing an opening in the nipple of fluid flow restricting small size and a partition diaphragm in the nipple cavity with a second opening also for restricting liquid flow. The two openings cooperate to limit liquid flow in response to the suction created by a baby. The partition opening is larger than the nipple opening to permit the desired fluid flow due to the reduced pressure drop across the partition created by the restricted opening size in the nipple body. The partition forms a small chamber in the nipple to limit the volume of liquid that a baby can withdraw at a time. Different embodiments are disclosed wherein the opening in the partition may be a hole of different shapes or a slit, or it may be a separate element attached to the nipple by the ring cap. The slit opens into an opening of a desired magnitude by flexure of the partition in response to the suction pressure differential thereacross.