1904] KEARNEY: PLANTS OF SEA BEACHES AND DUNES — 429 
3°" of soil taken here had an electrical resistance too high to be 
read with the instrument used; indicating an amount of soluble 
salt too small to warrant carrying the boring deeper. 
On the Virginia coast, a 9*™ boring was made into a low dune, 
just inside the outermost line of dunes (that which forms the 
landward limit of the beach proper). Here again the soil was a 
nearly pure quartz sand containing merely a trace of vegetable 
matter. While moist very nearly to the surface, the sand at a 
depth of 6-9" had a considerably greater water content and was 
also decidedly coarser than that nearer the surface. The vegeta- 
tion consisted solely of a showy grass, the ‘sea oats” (Uniola 
paniculata).*° Here the first 3°" of soil contained about 0.004 
per cent. of water-soluble salts, the second also about 0.004 per 
cent., and the third about 0.007 per cent. . 
Another 9“™ boring was made where a break occurred in the 
line of low outermost dunes, not far above the reach of the high- 
est tides (as was shown by the presence of much driftwood just 
beyond), but at least 6™ back from the actual limit of high tide 
at the time the boring was made. It was about 2™ nearer the 
beach than the boring just described. Here the vegetation con- 
sisted of Ammophila and Panicum amarum minus. The soil was 
a rather fine, nearly pure quartz sand, moderately moist in the 
first 3°", quite moist below that depth. The salt content of the 
first 3°" was about 0.03 per cent., of the second about 0.02 per 
cent., and of the third also about 0.02 per cent. Hence, for the 
9 column of soil the proportion of soluble salts to total weight 
of soil was here about five times as great as in the dune covered 
with Uniola. This large difference is not easy to explain, 
- although a somewhat smaller salt content in the dune would 
naturally be expected, as it was higher above sea level and 
farther from the high tide line. 
It was of course anticipated that borings made on the beach 
0 An account of this grass, as well as of other plants mentioned here, is given by 
the writer in his papers on “The plant covering of Ocracoke Island,” Contrib. U. S. 
erb. 5: 261-319. 1900, and on “A botanical survey of the Dismal Swamp 
region,” 767d. 321-550. 1901. A general ecological-geographical description of 
the vegetation of the North Catolita and Virginia strand is presented in the papers 
cited 
