Furthermore, all the daughter languages have a segment and those with long vowels generally have long . Until the mid-20th century, PIE was reconstructed with all of those vowels. Modern versions incorporating the laryngeal theory, however, tend to view the vowels as later developments of sounds that should be reconstructed in PIE as laryngeals . For example, what used to be reconstructed as PIE is now reconstructed as ; are now reconstructed as , *H representing any laryngeal; and has various origins, among which are a "syllabic" (any laryngeal not adjacent to a vowel) or an next to the "a-coloring" laryngeal . (Though they may have "phonetically" contained the vowel in spoken PIE, it would be an allophone of not an independent phoneme.) Some researchers, however, have argued that an independent phoneme *a must be reconstructed, and it cannot be traced back to any laryngeal.