292 BOTANICAL GAZETTE [OCTOBER 
data as to the amount of salt in the reclaimed marsh are 
unfortunately scanty, but it seems safe to say that it must be on 
the best marsh much less than half of 1 per cent. and it grades 
from that upward in all degrees to the wild marsh, which may 
contain up to 4 per cent., or, in special places, considerably 
more. It is the presence of this salt even in the reclaimed 
marsh, which, more than any other cause, keeps the marshes 
treeless; the salt prevents that ready osmotic absorption essen- 
tial to large vegetation. 
The distribution of salt in the reclaimed marsh is not uni- 
form, however, for places occur in which the vegetation exhibits 
- markedly, or even extremely, a salt-marsh character. These 
places are of three sorts. First, there occur certain ‘bald spots,” 
of no apparent determinants, on which only scanty salt-marsh 
plants grow, or, in certain cases, none at all. These may be 
remnants of ancient pools mentioned in the preceding para- 
graph. They can be rendered productive, however, which is 
effected by covering them with brush (branches of spruce, etc.), 
straw, loose boards, or other convenient material for two or three 
years, after which they bear the ordinary grasses of the surround- 
ing marsh. Of course this comes about through the fact that 
the rain washes out the salt from this soil, and the ground being 
protected from evaporation, no new supply is brought to the sur- 
face by the rising water. Second, on marsh that is improperly 
drained, there are occasional low spots into which the rain settles 
from the neighboring higher parts, of course carrying with it 
some dissolved salt which is concentrated as the water evaporates, 
thus allowing only a salt vegetation. Third, the farm roads 
across the marshes, though little used, are always marked by 
lines of salt plants, often indeed in most striking contrast to the 
rich hay grasses on each side of them. The presence of the 
greater quantity of salt along the roads is due, I believe, to a 
cooperation of two causes; first, the travel over such roads 
tends to keep down the grasses and to leave the ground some- 
what bare, so that evaporation from these places is much more 
rapid than from the neighboring densely grass-clad ground and 
the salt must therefore be drawn to the surface more abundantly 
