The Peripatetic History of Middle English *ѓթ 17Figure 1.1 Schematic diagrams of Merger-by-Transfer (A) and Merger-by-Approx-
imation (B) of two phonemes /X/ and /Y/. In merger-by-transfer, lexical
items containing /X/ gradually come to contain /Y/ instead. In merger-
by-approximation, the realizations of /X/ and /Y/ gradually approach
each other in phonetic space, until they cannot be differentiated.