W.S. Merwin's incumbency as judge of the Yale Series of Younger Poets competition is remarkable for two reasons. Firstly because he is the first winner of the competition (in 1952) to become its adjudicator later (in 1997); secondly because he is only the second judge since the competition's founding in 1919 to refuse to elect a winner, as he did in his first year in the post. (The other abstainer was W.H. Auden in 1957, five years after he had awarded the prize to Merwin for his A Mask for Janus.)

In 1998, Merwin selected as best of around 700 submissions Craig Arnold's manuscript, Shells. A doctoral candidate at the University of Utah, Arnold's book - recently published by Yale University Press in a handsome and elegantly designed volume - is also a draft of his dissertation.

Shells reads as a suite rather than as a loosely bound collection. Recurrent themes - food, friendship, parenting, among others - unify the poems and give the book a ranging continuity. Images of shells recur: in the ocean and the kitchen, in memory and in collections and private museums.

The hermit crab becomes an associated motif when invoked in the first poem. This drifter lives where he can, in the empty shells of whelks and other molluscs: 'he wears each welcome / out in its turn, and turns himself out creeping / unbodied through the sand, grinding and rude'. This 'weird housekeeping' becomes an evocative image ...