cooperating means on {TAIL ~ each} of {HEAD ~ said display cases} for retaining adjacent display cases releasably in vertically stacked relation for pivotal movement of their front and rear compartments as units about a common vertical axis, and 
cooperating means on { TAIL ~ each } of { HEAD ~ said display cases } for retaining adjacent display cases releasably in vertically stacked relation for pivotal movement of their front and rear compartments as units about a common vertical axis , and
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH