294 _ BOTANICAL GAZETTE [OCTOBER 
Animals.—Animals through divers of their manifold activi- 
ties may play a large part in phytoecology, but in the case of 
these marshes their influence appears with but one important 
exception to be imsignificant. That exception is the animal 
commonly called man, who has developed the habit of provid- 
ing himself with food by cultivation (in which respect he is by 
no means unique, but was long anticipated by the fungus-raising 
ants and others), and to this end has performed two opera- 
tions of much importance in the ecology of the marshes: first, 
he has shut out the sea from great areas, thus allowing their 
conversion from a salt to a nearly saltless soil with the enormous 
change in their vegetation thus implied; and second, he has 
brought from other countries certain special kinds of plants 
which he has let run wild on these marshes. The latter point 
needs especial emphasis, since it is so liable to be misunderstood. 
A stranger, even a botanist, visiting for the first time the 
reclaimed marshes, and looking upon their extensive fields of 
rich grasses, is likely to think that they are kept in that condi- 
tion only by careful sowing and frequent renewal, in the absence 
of which they would soon be replaced by other vegetation. This 
is what would soon happen on good upland hay fields, for 
instance, which soon revert to patches of wild weeds and later 
to forest. But such I. believe would be not at all the fate of 
these marshes. It is of course true that if they were totally neg- 
lected by man, the drains would soon fill up, and the dikes 
would be broken down and washed away, after which the whole 
region would return to the condition of wild salt marsh. But if, 
in some way the dikes and drains could be made perpetual, I 
believe that the present English hay grasses could maintain 
themselves indefinitely, or at least as long as the fertility of the 
marshes lasts, without care from man, and they would not as a 
whole be replaced by any other vegetation. In other words, the 
English hay grasses brought in by man appear to be the very 
vegetation best adapted to the conditions prevailing on the 
reclaimed marsh, and no other, certainly no native plants, could 
drive them out. Many facts sustain this rather remarkable con- 
clusion, of which the most important is this, universally stated 
