have otherwise been lost. The 9th–12th century texts of Zoroastrian tradition suggest that there was once a much larger collection of written Zoroastrian literature, but these texts — if they ever existed — have since been lost, and it is hence not known what script was used to render them. The question of the existence of a pre-Sassanid "Arsacid archetype" occupied Avestan scholars for much of the 19th century, and, "[w]hatever may be the truth about the Arsacid Avesta, the linguistic evidence shows that even if it did exist, it can not have had any practical influence, since no linguistic form in the Vulgate can be explained with certainty as resulting from wrong transcription and the number of doubtful cases is minimal; in fact it is being steadily reduced. Though the existence of an Arsacid archetype is not impossible, it has proved to contribute nothing to Avestan philology." Genealogy and script The Pahlavi script, upon which the Avestan alphabet is based, was in common use for representing various Middle Iranian languages, but was not adequate for representing a religious language that demanded precision since Pahlavi was a simplified abjad syllabary with at most 22 symbols, most of which were ambiguous (i.e. could represent more than one sound). In contrast, Avestan was a full alphabet, with explicit characters for vowels, and allowed for phonetic disambiguation of allophones. The alphabet included many characters (a, i, k, t, p, b, m, n, r, s, z, š, xv) closely resembling Book Pahlavi of the early Islamic Persia, while some (ā, γ) are characters that only exist in the older (6th-7th c. AD) Psalter Pahlavi script (in later cursive Pahlavi γ and k have the same symbol). Some of the vowels, such as ə appear to derive from Greek cursives. Avestan o is a special form of Pahlavi l that exists only in Aramaic signs. Some letters (e.g. ŋ́, ṇ, ẏ, v), are free inventions. Avestan script, like Pahlavi script and Aramaic script also, is written from right to left. In Avestan script, letters are not connected, and ligatures are "rare and clearly of secondary origin". Letters In total, the Avestan alphabet has 37 consonants and 16 vowels. There are two main transcription schemes for Avestan, the newer orthography used by Karl Hoffmann and the older one used by Christian Bartholomae. Later, when writing Middle Persian in the script (i.e. Pazend), another consonant was added