a first flexible tube communicating by one end with said reservoir and by its other end with {HEAD ~ the suction side} of said pump for delivering said liquid from said {TAIL ~ reservoir} to said pump 
a first flexible tube communicating by one end with said reservoir and by its other end with { HEAD ~ the suction side } of said pump for delivering said liquid from said { TAIL ~ reservoir } to said pump
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH