On the characteristics of primitive Northern and the changes that had taken place in the language before the Viking period, see Noreen, P.G.(2)I, 521-526. On pp. 523-526 are summarized the characteristics of General Northern. Until 800 the Northern tongue was unitary throughout the Scandinavian North. In the Viking age dialectal differentiations began to appear, especially in O. Dan. These are as follows (from Noreen): About 800, older _hr_ > _r_ in Denmark. Soon after 800, older diphthongs became simplified in Denmark, e.g., _au_ > _u_ cp. O. Ic. _þau_, O.Gutnic _þaun_ = O. Dan. _þusi_ pronounced _þøsi_. _ai_, _ei_ > _i_ cp. O. Ic. _stein_, O.N. _stæin_, O.Gtnc. _stain_ = O. Dan. _stin_. _io_, _iau_ > _u_ cp. O.N., O. Ic. _briote_, O.Gtnc. _briauti_ = O. Dan. _biruti_. Before 1000, _ē_ > _æ_ cp. O.N., O. Ic. _sér_ = O. Dan. _sær_ (written _sar_). About 1,000, appears in O. Sw.--O. Dan. an excrescent _d_ between _nn_ and _r_, e.g., _mantr_, pronounced _mandr_ (see Noreen, p. 526). 7. OLD NORSE AND OLD DANISH. Not until the year 1,000, or the beginning of the 11th Century, do dialectal differentiations seem to be fully developed. O.N., which in general preserves best the characteristics of the old Northern speech, undergoes at this time a few changes that differentiate Dan. and Norse still more. O. Sw. remains throughout closer to O. Dan. The two together are therefore called East Scandinavian. Old Icelandic, that is, Norse on Icelandic soil, develops its own forms, remaining, however, in the main very similar to O.N. These two are then called West Scandinavian. The following are some of the chief differences between West and East Scandinavian at the time (from Noreen, P.G.(2)I, 527): 1. _I_--(_R_) and _U_--_Umlaut_ in W.S. Absence of it in E.S., e.g., W.S. _hældr_ E.S. _halder_. 3 sg. pres. of _halda_, "to hold." W.S. _i gær_, "yesterday," E.S. _i gar_. W.S. _lǫnd_, pl. "land," E.S. _land_. 2. Development of _i_, _e_, _y_ into a consonantal _i_ in diphthongs in W. S., not so in E. S., e.g., W.S. _siá_, "to see," E.S. _sēa_. W.S. _fiánde_, "enemy," E.S. _fiande_. W.S. _biár_, "of a village," E.S. _býar_. 3. Assimilation of _mp_, _nk_, _nt_, respectively, to _pp_, _kk_, _tt_ in W.S., retention of them in E.S., e.g., W.S. _kroppen_, "crippled," E.S. _krumpin_. W.S. _ækkia_, "widow," E.S. _ankia_. W.S. _batt_, "bound," E.S. _binda_. pret. of _binda_, 4. The Medio-passive: W.S. _sk_, e.g., _kallask_, E.S. _s_, _kallas_. 5. Pronominal forms: W.S. _ek_, _vér_ (_mér_), E.S. _iak_, _vīr_, _ér_ (_þer_), _sem_, _īr_, _sum_. 8. REMARKS.