What passing-bells for these who die as cattle? a
-- Only the monstrous anger of the guns. b
Only the stuttering rifles' rapid rattle a
Can patter out their hasty orisons. b
No mockeries now for them; no prayers nor bells; c
Nor any voice of mourning save the choirs, -- d
The shrill, demented choirs of wailing shells; c
And bugles calling for them from sad shires. d
What candles may be held to speed them all? e
Not in the hands of boys but in their eyes f
Shall shine the holy glimmers of goodbyes. f
The pallor of girls' brows shall be their pall; e
Their flowers the tenderness of patient minds, g
And each slow dusk a drawing-down of blinds g

The rhyme-scheme of the poem is unusual. At first, it looks as if it will have a typical "Shakespearean" rhyme-scheme (ababa cdcd efef gg).  However, in the third quatrain (the third grouping of four lines), Owen does something unusual and unexpected, using the kind of quatrain typical of a Petrarchan sonnet (the first eight lines of which rhyme as follows (abba abba). Thus, the second sentence of the following Wikipedia article is incorrect (a good example of why Wikipedia can't always be trusted):  http://en.wikipedia.org/wiki/Anthem_for_Doomed_Youth