IN HIS article on Webern's variations,1 Robert U. Nelson quotes Webern on fourth variation of second movement of his Symphony, Op. 21: it is the midpoint of whole movement, after which everything goes backward. Finding that entire movement does have certain palindromic aspects, Nelson can diagram and discuss some correspondences between theme and coda, variations 1 and 7, 2 and 6, 3 and 5; and he points to an axis of movement in m. 50, center of variation 4. He is somewhat tentative about matter, however: the correspondence between this [fifth] variation and number 3, claimed by Webern, would seem to consist in [etc.].... [The] similarity [of variation 6] to variation 2 may lie in [etc.] (my italics). And he concludes that evidence for such paired relationships ... is at times imprecise and But Nelson fails to introduce clinching evidence. An investigation of particular row forms and row transpositions chosen by Webern for use in each section of movement, and of some related matters, bears out precision of Webern's comment and makes Nelson's tentative elucidation of movement's total symmetry anything but conjectural. The single row from which symphony is composed is symmetrically organized as an intervallic palindrome: its second hexachord is, intervallically, a retrograde of first. Because of this structure, one may speak of only six levels of prime form (Po-P5), of its inversion (Io-I5) and of their retrograde forms (Ro-R5, RIo-RI5), since P6 = Ro, I6 = RIo, etc., as shown in Ex. 1. In second movement of symphony, theme, each of variations, and coda reflect this symmetrical structure of row in various ways and to various degrees, some of them pointed out by Nelson. The following discussion concentrates on that aspect left unmentioned by him, Webern's choice of row forms and row transpositions. The melodic theme of movement (in clarinet) is based on RI2; its accompaniment is based on 12. The coda uses these, and only these, forms of row, so combined that music (as in most of variations, although not theme) is a symmetrical expression itself, centered on silent m. 94. One nicety of relationship between theme and coda, reflected in others of paired variations, is that whereas theme begins with RI2, followed by I2 in accompaniment, situation is reversed in coda: harp's low B (m. 89) begins coda's unfolding of 12; its high f, one eighth note later, begins RI2. Variations 1 and 7 are similarly equivalent in row forms utilized. The double canons of variation 1 expose four forms of row (followed by their respective retrogrades): I3 (violin 1) is shadowed in canon by inversion by Pi (cello), RI3 (violin 2) by R1 (viola). In variation 7, a more complicated texture