and (later) demotic. There was also a form of cursive hieroglyphs, used for religious documents on papyrus, such as the Book of the Dead of the Twentieth Dynasty; it was simpler to write than the hieroglyphs in stone inscriptions, but it was not as cursive as hieratic and lacked the wide use of ligatures. Additionally, there was a variety of stone-cut hieratic, known as "lapidary hieratic". In the language's final stage of development, the Coptic alphabet replaced the older writing system. Hieroglyphs are employed in two ways in Egyptian texts: as ideograms to represent the idea depicted by the pictures and, more commonly, as phonograms to represent their phonetic value. As the phonetic realisation of Egyptian cannot be known with certainty, Egyptologists use a system of transliteration to denote each sound that could be represented by a uniliteral hieroglyph. Egyptian scholar Gamal Mokhtar argued that the inventory of hieroglyphic symbols derived from "fauna and flora used in the signs [which] are essentially African" and in "regards to writing, we have seen that a purely Nilotic, hence African origin not only is not excluded, but probably reflects the reality" although he acknowledged the geographical location of Egypt made it a receptacle for many influences. Phonology While the consonantal phonology of the Egyptian language may be reconstructed, the exact phonetics are unknown, and there are varying opinions on how to classify the individual phonemes. In addition, because Egyptian is recorded over a full 2000 years, the Archaic and Late stages being separated by the amount of time that separates Old Latin from Modern Italian, significant phonetic changes must have occurred during that lengthy time frame. Phonologically, Egyptian contrasted labial, alveolar, palatal, velar, uvular, pharyngeal, and glottal consonants. Egyptian also contrasted voiceless and emphatic consonants, as with other Afroasiatic languages, but exactly how the emphatic consonants were realised is unknown. Early research had assumed that the opposition in stops was one of voicing, but it is now thought to be either one of tenuis and emphatic consonants, as in many Semitic languages, or one of aspirated and ejective consonants, as in many Cushitic languages. Since vowels were not written until Coptic, reconstructions of the Egyptian vowel system are much more uncertain and rely mainly on evidence from Coptic and records of Egyptian words, especially proper nouns, in other languages/writing systems. Also, scribal errors provide evidence of changes in pronunciation over time. The actual