Mechanical piston pipette

e, f, gThe mechanical piston pipette comprises a pipette body, a piston/cylinder assembly, the cylinder being arranged so as to be able to be equipped with a replaceable tip, and a tip ejector device, movable along the cylinder in order to eject a tip from the end of the cylinder. The pipette body accommodates an ejection actuation device and a piston actuation device effecting given longitudinal translational travel between a low limit stop position and a high limit stop position in order to perform the aspiration of an adjustable volume of liquid, with means of modifying said travel, means of adjusting the pipetted volume, means of displaying the pipetted volume and calibration means. Said adjustment means, said display means and said calibration means cooperate as an adjustment and calibration device in which, during a calibration operation, said display means are regulated so as to make the displayed volume equate with the pipetted real volume and said adjustment and calibration device is housed inside the pipette body.