PHONOLOGY 105 are in substantial agreement with each other in the distribution of the vowels a , e, 0 . Furthermore the palatalisation of the velar series which occurs in lndo-Iranian before a only when it corresponds to e in the other languages (ca — Lat. que, etc.) testifies to its existence in these positions in the prehistoric period of Indo- Iranian. The confusion of a and 0 is found also outside lndo-Iranian, in Germanic, Slavonic and Hittite. It is not possible to say for certain whether we have here independent parallel development in the various language groups, or whether th is fus ion of 0 and a is an ancient dialectal feature of Indo - European. Certainly in the case of lndo-Iranian and Slavonic, which show other signs of special affinity, the possibility of an ancient common change is deserving of consideration. The change e to a o n the ot her hand is found only in lndo-Ira nian, and it is one of the most characteristic features distinguishing this family from the rest of Indo-European, The lndo-Iranian development of the sonant nasals (to a) is the same as that of Greek, and it is one of the several features that links these two branches. Sonant nasals as such are found nowhere, but have been reconstructed for Indo-European from theoretical considerations. The sonant liquids have in the same way been replaced in most languages by combinations of vowel + r or /. Only lndo-Iranian preserved the vocalic r, which repre- sents also original vocalic l. In Sanskrit there exists only one case of vocalic l , namely the root kip - 4 to arrange Because of Vedic kfp Av. kshrp- 4 form, body which are usually compared with Lat. corpus it is generally considered that this / is of secon dary origin , but this is not altogether certain. Neverth? less as a general rule Sanskrit is much more consistent in turn* ing / into r in its vocalic form than in its consonantal form. On the basis of sonant f (which is attested in lndo-Iranian) and the sonant nasals can be safely reconstructed. They occur in the same conditions, that is to say by the suppression of the associated guna vowel which leaves them to function as vowels, and their treatment in various languages is similar. Thus we have for f in Gk. ap{pa), in Balto-Slavonic ir and in Germanic ur similarly for n Gk, a, B. SI. in, Germ. un. It is clear that the assumption of original sonant nasals is as much necessary to account for the variation in the associated vowel in the various languages as it is by the principles of apophony which are briefly noted below.
