[…] process of assimilation […] under the same comprehensive head may be grouped the greater part of the other phonetic changes that occur in language. The combinations of elements to form words, their contraction by the omission of light vowels, often bring into contact or into proximity sounds which cannot be so uttered without too much muscular exertion: it is eased by adapting the one to the other.
- Whitney (1875), a pag.70