{TAIL ~ The discs} may include inwardly directed notches formed in their outer perimeter, with the notches cooperating with {HEAD ~ an interior wall} of the housing to cut tissue specimens 
{ TAIL ~ The discs } may include inwardly directed notches formed in their outer perimeter , with the notches cooperating with { HEAD ~ an interior wall } of the housing to cut tissue specimens
TAIL TAIL TAIL TAIL TAIL TAIL 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