=Type D*= on the other hand does occur, but almost exclusively in the first hemistich. It has three sub-types: (i) D*1 –́ × | –́ × ×, _sī́de sǣ́næ̀ssas_ Beow. 223, _áldres órwḕna_ Beow. 1002; with resolution of the first arsis, _ǽðeling ā́nhȳ̀dig_ Beow. 2668; more commonly with resolution of the second arsis, _mǣ́ton mérestræ̀ta_ Beow. 514; with resolution of both, _lócene léoðos[`y]rcan_ Beow. 1506. (ii) D*2 –́ × | –́ ⏑̀ ×, _mǣ́re méarcstàpa_ Beow. 103, _éaldor Éastdèna_ Beow. 392; with resolution of the first arsis, _ǽðele órdfrùma_ Beow. 263; with resolution of the second arsis, _mṓdges mérefàran_ Beow. 502, _Bḗowulf máðelòde_ Beow. 505, &c. (iii) D*3 –́ × | ⏑́ ×̀ × is not found. (iv) D*4 –́ × | –́ × ×̀ is rare, _grḗtte Gḗata lḕod_ Beow. 625, _þrȳ́ðlīc þégna hḕap_ Beow. 400; with resolution of first arsis, _éaforan éllorsī̀ð_ Beow. 2452; with resolution of the second, _ȳ́ðde éotena c[`y]n_ Beow. 421; with resolution of the secondarily accented syllable, _wī́n of wúndorfàtum_ Beow. 1163; this type is varied by anacrusis, _ongínneð gḗomormò̄d_ Beow. 2045, and by anacrusis together with disyllabic thesis in the second foot, _oferswám þā síoleða bigòng_ Beow. 2368. =Type E*= does not occur in O.E. poetry.[78] § =31.= To assign the different hemistichs of a poem to these various types we have to follow as a regulating principle the natural word accent and syntactical accent of each sentence. In some cases the similarity or relation with one another of the types renders it a matter of difficulty to determine exactly to what particular type a hemistich may belong. Systematic investigations as to the principles which govern the combinations of the five types in pairs to form the long line have not yet been made. From such observations as have been made it would appear that by preference hemistichs of different rhythmical structure (ascending and descending) were combined with a view to avoid a monotonous likeness between the two halves of the verse.[79] § =32.= The combination of two hemistichs so as to form a long line is effected by means of alliteration, one at least of the two fully accented syllables being the bearer of an alliterative sound. In no case is an unaccented syllable or even a syllable with a secondary accent allowed to take part in the alliteration. This fact, that secondarily accented syllables are debarred from alliterating, is another proof that it is better to look on them as belonging to the thesis rather than to the arsis of the verse. =The Principles of Alliteration.=