The pipettes, 40 and 42, are positioned and operated by a pipette mechanism 44 mechanically connected to {HEAD ~ the pipettes} 40 and 42, as indicated by {TAIL ~ dashed lines} 
as indicated by
The pipettes , 40 and 42 , are positioned and operated by a pipette mechanism 44 mechanically connected to { HEAD ~ the pipettes } 40 and 42 , as indicated by { TAIL ~ dashed lines }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL