said plate member and said {HEAD ~ floor} further cooperating to allow gas to seep from {TAIL ~ said compartment} to said chamber for providing a substantially uniform gaseous environment in said chamber 
said plate member and said { HEAD ~ floor } further cooperating to allow gas to seep from { TAIL ~ said compartment } to said chamber for providing a substantially uniform gaseous environment in said chamber
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH