As will be apparent from the foregoing description, cartridge 24 forms {HEAD ~ a self contained, disposable unit}, which may be easily replaced when the stock of {TAIL ~ membrane} 28 on roll 26 is exhausted 
As will be apparent from the foregoing description , cartridge 24 forms { HEAD ~ a self contained , disposable unit } , which may be easily replaced when the stock of { TAIL ~ membrane } 28 on roll 26 is exhausted
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH