Sign base morphology
here refers to those morpheme-base morphological frameworks which assume that every morpheme is a linguistic sign, a mutually implied pairing of sound and meaning. Although this notion is associated with Saussure because of his famous illustration of the the coffee-bean containing the word for 'tree' and a picture of a tree, Baudouin de Courtenay (1895
) and Bloomfield (1933
) are more directly responsible for introducing the concept to the discipline. Saussure, in fact, went to great pains to point out the problems with the assumption of sign-based morphology and never used the term 'morpheme' in his lectures.