FROM THE AVAILABLE DATA IT IS POSTULATED THAT FIBRES ARE MECHANICALLY TRANSFERRED BY THE FOLLOWING THREE PROCESSES. SOME FIBRES ALREADY EXIST AS FRAGMENTS ON THE DONOR MATERIAL AND ARE EXCHANGED DURING THE CONTACT; A FEW FIBRES WHICH ARE RELATIVELY LOOSE IN THE YARN ARE PULLED OUT; AND FIBRES ARE ALSO PRODUCED BY DIRECT FRAGMENTATION OCCURRING DURING THE CONTACT ITSELF. THE CONDITIONS UNDER WHICH A PARTICULAR MECHANISM IS LIKELY TO PREDOMINATE ARE DISCUSSED. THE RESULTS OF THE PERSISTENCE STUDY DEMONSTRATE THAT FIBRES REMAIN ON CLOTHING DURING WEAR BY MEANS OF MECHANICAL INTERACTIONS WITH THE SURFACE OF THE RECIPIENT GARMENT. IT IS SHOWN THAT THE FIBRE PERSISTENCE-VERSUS-TIME CURVES CAN BE WELL REPRESENTED MATHEMATICALLY BY ASSUMING THAT FIBRES ARE LOST BY FIRST ORDER KINETIC PROCESSES FROM THREE DISTINCT STATES OF MECHANICAL BINDING. THE DIFFERENT PERSISTENCEVERSUS-TIME CURVES OBTAINED FOR THREE PARTICULAR GARMENTS ARE INTERPRETED AS MEANING THAT THE THREE STATES OF BINDING ARE NOT SIMILARLY POPULATED SO FAR AS THESE GARMENTS ARE CONCERNED. THE IMPLICATIONS OF THE PROPOSED MECHANISMS ARE ALSO DISCUSSED IN CONNECTION WITH SOME PRACTICAL PROBLEMS, SUCH AS THE RETRIEVAL OF FIBRES FROM THE SURFACE OF CLOTHING. SEE ALSO NCJ-31070 AND 31071. (AUTHOR ABSTRACT)