This is how most old Cape Cod houses were framed and plastered years ago. The wooden lath strips were nailed to the framing, then covered with clam shell (or horse hair) plaster. The plastering was sometimes done in two layers. A horse hair base coat was applied first. Then the finish plaster was applied over the basecoat.

The wall here has been stripped of plaster and wood lath, but you can see the lath strips and the old plaster that oozed through the laths on the other side of the wall framing.

Notice the framing. Back in the old days most of the wood used for framing was recycled from ships, barns, saltworks, or elsewhere. When remodeling old Cape Cod houses you often find that most of the framing stock is uneven or of non-uniform widths. This particular image was from a remodel that was done in East Dennis near Sesuit Harbor a few years ago.