Snowflake of ice. At that stage, the snowflake has the shape of a minute hexagon. The six "arms" of the snowflake, or dendrites, then grow independently from each of the corners of the hexagon, while either side of each arm grows independently. The microenvironment in which the snowflake grows changes dynamically as the snowflake falls through the cloud and tiny changes in temperature and humidity affect the way in which water molecules attach to the snowflake. Since the micro-environment (and its changes) are very nearly identical around the snowflake, each arm tends to grow in nearly the same way. However, being
Front and back However, acoustically there is little difference between a central vowel and a back vowel, with the result that the two are frequently grouped together into an even broader category of "back vowels", or a category of "non-front vowels". A back consonant includes all consonants whose place of articulation is in the soft palate (velum) or farther back, including velar, uvular, pharyngeal, and glottal consonants. From the perspective of primary places of articulation, this includes all of the laryngeal consonants and some of the dorsal consonants (specifically, excluding palatal consonants). A front consonant includes all consonants that are not back consonants,