But Greek and Latin are quite unequal, when disjoined from the elder wheels in our etymological system, to the working of the total machinery of the English language. Mr. Landor proceeds upon no fixed principles in his changes. Sometimes it is on the principle of internal analogy within itself, that he would distort or retrotort the language; sometimes on the principle of external analogy with its roots; sometimes on the principle of euphony, or of metrical convenience.
Source: wiktionary