the hair, Jervis, and inside the wound. They tell us something, I think."
I examined, through my lens, the chalky fragments to which he pointed. "These seem to be bits of shells and the tubes of some marine worm," I said.
"Yes," he answered; "the broken shells are evidently those of the acorn barnacle, and the other fragments are mostly pieces of the tubes of the common serpula. The inference that these objects suggest is an important one. It is that this wound was produced by some body encrusted by acorn barnacles and serpulæ; that is to say, by a body that is periodically submerged. Now, what can that body be, and how can the deceased have knocked his head against it?"
"It might be the stem of a ship that ran him down," I suggested.
"I don't think you would find many serpulæ on the stem of a ship," said Thorndyke. "The combination rather suggests some stationary object between tidemarks, such as a beacon. But one doesn't see how a man could knock his head against a beacon, while, on the other hand, there are no other stationary objects out in the estuary to knock against except buoys, and a buoy presents a flat surface that could hardly have produced this wound. By the way, we may as well see what there is in his pockets, though it
