174 THE FORMATION OF NOUNS other than the neuter yugdm. The m in the neuter yugdm was originally the w-suffix, but owing to similarity 'with the accusa- tive singular of thematic stems (originally all adjectival and of common gender), it came, by an easy process of adaptation, to be treated as a termination, with the consequence that forma- tions of this kind were turned into neuter thematic stems and declined accordingly. The neuter thematic type then became productive, particularly in forming extensions of neuter con- sonantal stems (- ana , -atra, etc., above). The relation that exists between yugdm and yugmd appears also between bhaydm ' fear ' : bhlmd - 1 fearful J and mddhyam nt. middle : madhyam-d- adj. 1 being in the middle The adv. sddam can be explained as a neuter m-stem in view of the deri- vative s adman- ‘ seat ' ; likewise dram , dlam ‘ fittingly, suit- ably ’ from the IE root ar- ‘ to fit J by comparison with deriva- tives like Gk. app6$. Ancient thematic neuters in IE are very rare, Skt. yugdm is shown to be ancient by the correspondence of Gk. t^vyov, Lat. iugum , etc. Another ancient word is Skt. paddm r step Gk. irihov, Hitt, pedan, which may be presumed to have originated in the same way, though direct evidence is lacking in this case. Gk. €pyov * work ' with the same rare and no doubt ancient apophony as ttsSov is to be classed with it. It should be noted that such primitive thematic neuters, which according to this theory are transformed m-s terns, are not only exceedingly rare, but they are the only class which provide certain word equa- tions between different IE languages. Thus the thematic neuters of secondary origin, namely (i) extensions of neuter consonantal stems and (2) the still later though numerous taddhita formations, are of later origin. It would be difficult otherwise to explain the absence of detailed agreement among these formations between the various languages. In this con- nection also we must note the complete absence of the latter two formations in Hittite. The rarity of the thematic neuter formations of the type paddm , yugdm shows that, although this was one way by which the primitive m-stems were removed, and although it provides the only plausible explanation for the existence of neuter thematic stems at all, this was not the only, or indeed the main way by which this was done. The other process which operated and which accounted for many was the extension of m-stems
