388 The Botanical Gazette. [October, 
germs to the water level and thus raises the average greatly 
for the time being at least. Then another cause is the greater 
rapidity of multiplication in these waters on account of the 
higher temperature. 
Comparisons can scarcely be made under equal conditions 
between the bacteria found in streams and springs and those 
inhabiting the ocean. The proportions existing between the 
waters of our great inland seas and that of the ocean would 
be much more reliable but as we have no data concerning the 
bacterial contents of these large fresh water masses, this can 
not at present be made. : 
In the light of our present knowledge, the assertion seems 
to be warranted that marine waters are not as rich in bactet 
ial life as frésh water masses. 
tions like the sea, yet it would not be unreasonable to vp 
pose that these organisms would slowly tend to settle to "7 
bottom in obedience to a universal law. Especially ie 
this be likely with forms that are in a spore condition, gis 
are immotile and of higher specific gravity than active P 4 
lasm. 
: But the question as towhether there isa ‘perpetual aries 
of germ life on the sea bottom is not so easily answe 
number of opposing factors enter into the questio és 
it difficult to say what actually takes place under ape 
ditions. The experiments of Bolton, and peat ‘onl 
settling of bacteria in tall cylinders do not give 4 y atanced 
answer, for the natural increase oA growth is counterd: 
by the constant dying off of old forms. se germs 
A Ntotility is adowlicr factor of the pe aa ae ome 
endowed with locomotor powers are easily able 
the effect of gravity. 
ficial and | 
baste ked differ 
__ This season’s work substantiates the ees deeper lay 
-year and leads us to the conclusion that ‘Whether this is 
_as rich in bacterial life as the surface. _WOS == = 
5Die Wasserversorgung von Ziirich. 1885. 
