428 
BOTANICAL GAZETTE 
[JUNE 
Turning now to the beach and dune sands the results are tab- 
ulated for convenient reference as follows: 
Salt content (in percentages of soil) at 
E various depths 
Locality Situation where sample was taken 
o-3 dm 4-6dm 7-9dm 
Woods Hole,Mass.| Dune marsh OE Behe ge ete OM et te 
* Ss Inner dune O. 008i ee ea a ee oe 
é Hy Beach, outer limit vegetation 0.006 Gy008 See 
as “* | Beach near outer limit vege- 
tation G. O08 9 6a el eaais 
Norfolk, Va. Low dune, inside outermost 0.004 0.004 0.007 
se a Break in outermost line dunes 0.03 0.02 -02 
es 2H Beach, outer limit vegetation 0.003 0.009 0.006 
“ 4 Beach, outer limit vegetation 0.004 0.003 0.003 
Long Beach, Calif.| Beach, near outer limit veg. 0.14 Par Daan earn 
= “i ee RS 0.12 Ay Eee ee ae 
“cs “ ae “oe ° 
«ee “ “ oi ome ns 
a a 3 4 0.15 5 ia eck: (oe SPO 
It is evident that we have here a condition as regards salt 
content of the soil quite different from that prevailing in the salt 
marshes. In order to a proper interpretation of these results 
some details of the examinations which yielded them must be © 
given. On the Massachusetts coast a small ‘dune marsh,” a 
level expanse among the dunes, covered with a thick carpet of 
vegetation— Utricularia cornuta, Oxycoccus macrocarpus, Drosera 
intermedia, Lycopodium inundatum—was first examined. Herea 
3°" boring into the coarse moist sand, of which the uppermost 
3-6°™ contained a little vegetable matter, revealed the presence 
of only about 0.003 per cent. of salt. But in view of the 
character of the vegetation no considerable amount of salt 
was expected here. 
An examination of the dunes themselves was the next step in 
A low dune, some distance inside the outer- 
Here the soil 
the investigation. 
most line of dunes, was selected for examination. 
was a nearly pure coarse quartz sand, practically devoid of humus, - 
and was quite moist immediately beneath the surface, as was 
found to be generally the case with the dune sands, as well as 
with those of the outer beach. This dune was covered with a 
growth of Ammophila arenaria and Hudsonia tomentosa. The first 
