320 The Botanical Gazette. [October, 
from this form, the other species were quite unlike, although 
they possess some similar characteristics. The bacteria that 
are so universally present in sea water and mud seem to be 
quite peculiar to this habitat. Of course many land and fresh 
water forms are carried into the sea by drainage, but sooner or 
later, most of them succumb to the changed conditions of 
their existence. 
With this zztroduced or adventive flora, we are not espec- 
ially concerned, but aside from this, there are these certain 
well defined species, that seem to be indigenous to this partic- 
ular habitat. By long residence in salt water, some of them 
have become so. modified, that they grow much more luxur- 
iently upon media made from sea water than upon that which 
contains only the normal amount of salt. In one of the spe- 
‘ he aus- 
Much of this class of work can be best done under th 5 
mmission 
r 
pices of the government, either by the Fish Co i rovided 
the Coast Survey, as these departments are alrea te dredg- 
with the necessary outfit of vessels fitted with suita 
ts 
yl 
pag aol 
