It is a well-known fact in linguistics that languages which are entirely without influence on one another often show a striking similarity in their development. The Indo-Iranian group is especially informative in this regard. Between the Indian and the Iranian divisions of the Aryan dialects a development may be traced which is frequently closely parallel. The change between the Sanskrit and the Pali-Prakrit in the Indian branch, as compared with the transition grade of the Pahlavi in Iranian, is due in great part to the long preservation of the Sanskrit as a learned language. The close attention to the preservation of the written language which is so marked in India never existed in Iran. It is found in Persia the successive changes in language recorded in the literature, while in India the Pali-Prakrit appear at once as finished languages. All coincidences between the Pali and the New Persian are due solely to the operation in both dialects of the laws of development which govern the Indo-Iranian languages in general.