Four islands, 8 to 13 miles f rom the mainland, separate the Mississippi coast from the Gulf of Mexico. These include Cat Island on the west, and Ship Island, Horn Island, and Petit Bois on the east. Horn Island is in Jackson County; the west end of the island, the longest one in the group, is 13 miles southeast of Biloxi, Mississippi, at approximately 300 13' N. and 88? 40' WV. The climate of Horn Island is mild; records available at Pascagoula, Mississippi, some 12 miles northeast, show a mean winter temperature of 52.9? F. and a mean summer temperature of 80.70 F. The highest temperature recorded at Pascagoula is 1010 F. and the lowest 160 F. The mean annual precipitation is about 58 inches, most of which falls during the warmer part of the year. Geologists believe that these coastal islands were at one time a part of the mainland, and that the entire Gulf coast is slowly sinking (McGee, 1891). The islands are separated from the mainland by a depression, which has become filled by the waters of the Gulf of Mexico, forming the Mississippi Sound. Soil samples taken at different places on Horn Island seem to substantiate this hypothesis, for in a number of places the soil is quite similar to that of the mainland. The nature of the bottom of the Sound, which is composed of hard clay, and the shallowness of the Sound, further substantiate this hypothesis of the origin of the islands and the sinking of the coast. Horn Island is 13 miles long and threefourths of a mile wide at its widest part. At the west end of the island is a sand bar approximately 2 miles long and at the east end another bar about one-half mile long (fig. 1). Between these sand bars the island is heavily wooded with slash pine.' Along the south (or Gulf) and north (or Sound) coasts, dune and beach sands form the major soils. In the interior of the island, are many depressions, some of which are inhabited by dune vegetation and others by marsh plants. In both conditions, Plummer fine sand predominates. This soil consists of fine, dark gray sand underlain by fine, white, water-soaked sand. This poorly drained soil supports scattered grass, which affords grazing for a hundred or more cattle. The sand bars at each end of the island are practically barren, the vegetation consisting mainly of widely scattered tufts of grass, with small patches of Croton and Hydrocotyle. Towards the interior of the island the ground rises to about 10 feet above sea level, and slash pine, together with an undergrowth of shrubs constitutes the major vegetation. On a few scattered patches on old dunes prickly pear occurs. At both the west and the east ends of the island sand dunes much higher than in the interior have buried tall pine trees to their crowns. Slash pine, the principal forest species, forms pure stands of various ages; the oldest trees measure 26 inches in diameter at breast height (d.b.h.) and are about 170 years old. Trees 12 inches or more d.b.h. are 90 to 100 years old, and those 8 to 10 inches d.b.h. probably are 40 to 50 years old. The reproduction ranges