Rowley Reef.—This photograph, taken on the same date as the preceding, shows another section of the reef, where the clam set has been torn up and destroyed by horse-shoe crabs and cockles.
Rowley Reef.—A photograph, natural size, of a thickly set part of the same flat. The broken shells on top show clams which have been crowded out of the sand and destroyed. In this way nature regulates the number of clams in a given area.
Castle Neck Flat (Essex River).—A scene at low tide, Aug. 28, 1907, showing the area turned over by two clammers in one hour. At this date there was a heavy set of small clams on this flat.
