Abstract: A device for discharging particulate material, such as agricultural seed at a uniform rate comprises a hopper having a rectangular slot in the base, a driven roller having a compressible surface which contacts one side of the slot and a transparent glass metering plate attached to the hopper and which bears against the roller to provide a nip therebetween and to control the rate of flow of the material from the hopper while allowing visual examination of the flow of particulate materials between the roller and metering plate. The device may be conveniently attached to an agricultural drilling machine and the roller driven by a mechanism associated with the ground wheels of the machine. Collecting cups are provided for directing the seed from beneath the roller into the seed drills. Seed is discharged into the drills at a constant rate and no adjustment is necessary for use with seeds of different sizes.