of vipers, nutrition for her vices" Greenberg (1980), who criticises Clarke's study as statistically unsound in some respects, compares Virgil and Lucretius. One of his conclusions is that Lucretius is more likely than Virgil to use three or more initially alliterating words in the same line, for example: "(we see) many things moving in many ways by various means" In order to simplify their investigation, neither scholar takes internal alliteration into account, or alliterations such as which spread over more than one line. However, Greenberg states: "There is no intrinsic reason why alliteration should be limited to the confines of a single verse or to word-initials." Certain letters are used in alliteration more frequently than others. In Virgil, according to Clarke, the commonest letters for word-initial alliteration are a, c, p, s, m, t, d, e, f, i, n, v; alliteration with b is very rare. However, when an alliterating word comes after a verse-break such as a caesura, the letter a is less common, coming only in 6th or 7th place. Usually a letter alliterates only with itself, but sometimes qu can alliterate with c; ph may alliterate with p; ae and au may alliterate with a; and sc, sp, st may alliterate with s. From both studies, it is clear that when only two words in a line begin with the same letter, it is difficult or impossible to identify objectively whether the alliteration is accidental or deliberate, since alliterated words occur no more often in any line than would be due to chance. To identify whether alliteration is present, more subjective criteria must be used, such as whether the two words are important for the meaning of the line. Thus although Lucretius 3.267 () is counted as an example of alliteration by Greenberg's computer programme, it is doubtful if alliteration can be made on a weak word such as "and". When two pairs of words alliterate in the same line, the order abab is most common, then aabb, then abba. An example of the last is the following from Virgil: "they exchange wounds with much violence" Although alliteration is common in Virgil, Ovid, and Lucretius, it is not found in every line. Overall, some 35-40% of lines in both Virgil and Ovid have no word-initial alliteration at all; in many of the remainder, the alliteration may well be accidental. Uses of alliteration Linking alliteration Frequently alliteration simply