These are for Ellen, Bob, and their new baby girl. The shells are freshwater "papershell" clams; I found them in the autumn of 2001, on the shore of a reservoir at the Middlesex Fells in Massachusetts. Discovering them—not sea shells, but lake shells!—was lovely, as was realizing that New England has bivalves so delicate they can be illuminated by the sun.

I had been thinking about making these boxes already for a while, even before Ellen and Bob decided to get married. I'd always known there would be three, so in August when Ellen said they'd made a 'honeymoon baby,' it seemed right that this should be their wedding gift.

Then it took another long while ... again, months, before the shells in their windowboxes looked as I'd imagined them. Since late this fall they've been ripening in my front window. They're almost ready. I think I have a year from the wedding to deliver the gift.

I didn't actually make it to the wedding last May. On the way through Rhode Island, we stopped off at a pond, and got caught up in watching a big old snapping turtle going on with her life. Somehow, at that moment, it made sense to stay longer in the woods, to miss the ceremony and turn up late, for the party. At the time this seemed right.

The animals that made and lived in these shells were mollusks; as with trees, the rings they produced tell a story about their lives. Mollusks are invertebrates, without bones inside, so their shells serve as skin and skeleton at once: protecting, revealing, and giving them shape. Underneath, the pearly, nacreous layer, the part closest to the animal, was excreted by its whole mantle, and so is smooth and luminous, while the ridges of the outer layers were produced at the edge, in waves over time.