This form of assonance is not found in English poetry, though it is employed in Celtic and Icelandic metres.[13] § =13.= The third species of rhyme, to use the word still in its widest sense, is known as alliteration (German _Stabreim_ or _Anreim_). It is common to all Teutonic nations, and is found fully developed in the oldest poetical monuments of Old Norse, Old High German, Old Saxon, and Old English. Even in classical poetry, especially in the remains of archaic Latin, it is not unfrequently met with, but serves only as a means for giving to combinations of words a rhetorical emphasis, and is not a formal principle of the metre bound by strict rules, as it is in Teutonic poetry. Alliteration consists in a consonance or agreement of the sounds at the beginning of a word or syllable, as in _love_ and _liking_, _house_ and _home_, _woe_ and _weal_. The alliteration of vowels and diphthongs has this peculiarity that the agreement need not be exact as in 'apt alliteration's artful aid', but can exist, at least in the oldest stages of the language, between all vowels indiscriminately. Thus in the oldest English not only were _ellen_ and _ende_, _ǣnig_ and _ǣr_, _ēac_ and _ēage_ alliterations, but _age_ and _īdel_, _ǣnig_ and _ellen_, _eallum_ and _æðelingum_ were employed in the strictest forms of verse as words which perfectly alliterated with each other. This apparent confusion of vowel-sounds so different in their quantity and quality is probably to be explained by the fact that originally in English, as now in German, all the vowels were preceded by a 'glottal catch' which is the real alliterating sound.[14] The harmony or consonance of the unlike vowels is hardly perceptible in Modern English and does not count as alliteration. The most general law of the normal alliterative line is that three or at least two of the four strongly accented syllables which occur in every long line (two in each section) must begin with an alliterative letter, for example, in the following Old English lines: _=w=ereda =w=uldorcining | wordum hērigen._ Gen. 2. _=m=ōdum lufien | he is =m=ægna spēd._ Gen. 3. _=æ=sc bið =o=ferhēah | =e=ldum dȳre._ Run. 26. _on =a=ndsware | and on =e=lne strong._ Gū. 264. or in early Modern English: _For =m=yschefe will =m=ayster us | yf =m=easure us forsake._ Skelton, Magnif. 156. _How sodenly =w=orldly | =w=elth doth dekay._ ib. 1518. _I am your =e=ldest son | =E=sau by name._ Dodsl. Coll. ii. 249.