Once we have obtained some notion of how a phoneme is formed, we may observe various 'modifications' in the way it is produced. [...] The most important of these is 'palatalization': during the production of a consonant the tongue and lips take up, so far as is compatible with the main features of the phoneme, the position of a front vowel, such as [i] or [e].
- Bloomfield (1935), a pag.117

Consonants are often assimilated to the tongue-position of preceding or following vowels. The commonest case is the assimilation especially of dentals and velars to a following front vowel; this is known as 'palatalization'.
- Bloomfield (1935), a pag.376