316 The Botanical Gazette. [October, 
The usual content of the sea water ranges from 10 to 150 
germs per cc., while in exceptional instances the number per 
unit of volume exceeded this; but the fact that the individu- 
als present were in these cases usually of a single species indi- 
cated that the large number was due to a bit of zovgloea 
rather than active vegetative forms. A comparison of salt 
with fresh water shows that on the whole bacterial life is less 
abundant in the sea than in fresh water. The higher tem- 
perature of the latter and its proximity to land masses, which 
are nearly always extremely rich in bacterial organisms, are 
sufficient to account for this increase. 
A bacteriological examination of the sea bottom shows 
that it, too, is filled with bacteria. 
Observation demonstrates that the sea-floor is infinitely 
richer in germ life than the waters above it. A quantitative ex- 
amination of the ocean bottom shows a wide variation in its 
bacterial contents. Just what factors bring about this differ- 
ence in numbers, I am unable, as yet, definitely to state, but it 
seems more than probable, that the variable physical charac- 
ter of the sea flora, the depth at which material is taken, and 
the influence of temperature are conditions which largely de- 
termine the presence of micro-organisms. As might be ex- 
pected, it will require an extended series of data gathered un- 
der similar as well as diverse conditions before the pee 
of distribution can be satisfactorily explained. I shall only 
attempt to submit certain facts which have been brought out 
by the work, leaving a definite explanation until more thor- 
ough investigation. 
At Naples, the investigation of the sea botto 
m was eee 
from the shore line to a depth of 3,500 feet. At the depth 0 
dence with . 
point. 
