PIPETTING DEVICES FOR MEASURING AND DISPENSING LIQUIDS THROUGH PIPETTES AND PIPETTING SYRINGES, PIPETTING SYRINGES, PIPETTE TIPS, MICRO-PIPETTES, MULTI-TIP PIPETTES, ADAPTERS FOR CONNECTING MULTI-TIP-PIPETTES TO PIPETTING DEVICES, AND PIPETTE RACKS ALL MADE FROM MOLDED PLASTICS MATERIAL