455 
3. ToraL STOCKS OF OXIDIZABLE MATTER IN THE RIVER AT 
CHILLICOTHE, 1914—1915 
Not only the plankton, but in addition all the other oxidizable matter 
carried in the stream-flow, whether suspended or dissolved, may be re- 
garded as potential detritus or as potential microorganisms, some portion 
of which, in some form or other, may be useful as food to the bottom 
animals or to the organisms on which they themselves feed somewhere in 
the course of the stream below the sampling point. If the total oxidiza- 
ble matter at Chillicothe 1909—1914 was in about the same ratio to the 
total nitrogen as in 1900—1902 (about ten times total nitrogen in the 
winter and spring months, and seven to nine times the nitrogen figures 
in midsummer and autumn), we would have had passing Chillicothe in 
the entire year, March, 1914, to February 1915 a total of 617,137 tons, or 
over 1,200,000,000 pounds total oxidizable matter, dry weight, or some 
sixty to a hundred and fifty times the total dry weight of the plankton 
that passed Havana in the twelve months September, 1909, to August, 
1910 (eight million to twenty million pounds). If this enormous total 
load could be settled out and apportioned equally to the approximate 
26,780 acres of river between Chillicothe and Grafton at gage 8 ft., Ha- 
vana, each acre would receive in the course of the year 46,086 pounds, 
an average equal to more than seventeen hundred times the average dry 
weight poundage (about 10 per cent.) of bottom animals per acre 
(twenty-six pounds) found in the summer of 1915 between Chillicothe 
and the river’s mouth. The employment of vertical instead of surface 
chemical samples for the determination of loss on ignition would with 
little question, also, show still higher values of total oxidizable matter 
than those here figured, particularly in seasons of recession from flood, 
when the dead suspended organic matter increases heavily in concentra- 
tion from the surface downward. (See table on p. 456.) 
4. Tue PorTION OF THE PLANKTON SETTLED OUT OR CONSUMED 
Basing the computations on percentage decreases in silk-plankton vol- 
umes (c.c. per m.*) between Havana and Grafton in June and August 
1910, and on rates of increase in discharge between Havana and the 
mouth of the river in the spring and midsummer months, but taking no 
account of normal multiplication, there is found for the nine-months 
growing season, March—November, 1909—1910, a total loss of plank- 
ton in the 120 miles below Havana of 243,503,139 Ibs., or almost exactly 
two thirds of the total stocks that passed Havana during the period 
(387,883,000 Ibs.). The dry weight of this lost plankton at 5% (12,- 
175,156 lbs.) amounts to nearly 30 times the dry weight, estimated at 
10%, of the bottom animals found in 1915 in approximately the same 
reach of river in which the loss occurred (total bottom-fauna stocks 
Copperas dam—Grafton, 1915, 4,277,350 lbs; dry weight at 10%, 427,- 
%35 Ibs.). 
