Indo-European had had two "sonantic coefficients", vanished sounds that had two properties: they lengthened a preceding vowel; one of them gave the vowel e or a timbre, while the other gave the vowel o timbre.

Saussure's argument was not accepted by any of the Neogrammarians, the school, primarily based at the University of Leipzig, then reigning at the cutting-edge of Indo-European linguistics. Several of them attacked the Mémoire savagely. Osthoff's criticism