William Clarke (1976) and Nathan Greenberg (1980) offer an objective framework for the study of alliteration in Latin poetry. However, their definition of alliteration as word initial sound repetition in a verse is inconsistent with the syllabic nature both of the device itself and also of the metrical structure. The present study reconciles this disparity in the first half of the Aeneid by applying a similar method to syllable initial sound repetition. A chi-square test for goodness-of-fit reveals that the distributions of the voiceless obstruents [p], [t], [k], [k^w], [f], and [s] and the sonorants [m], [n], [l], and [r] differ significantly from a Poisson model. These sounds generally occur twice per verse more often than expected, and three or more times per verse less often than expected. This finding is largely consistent with existing observations about Vergil's style (e.g. Clarke, 1976; Greenberg, 1980; Wilkinson, 1963). The regular association of phonetic features with differences in distribution suggests phonetic motivation for the practice.