82 ILLINOIS BIOLOGICAL MONOGRAPHS [180 
below the Champaign outlet. Algae and animal life were noted, but not as 
abundantly as in the sludge bank at the junction of the Salt Fork and Bone- 
yard (Fig. 21). 
Animals Blue-green algae 
Euglena geniculata, very few. Phormidium inundatum, abundant. 
Paramoecium, one specimen. Diatoms 
Vorticella, very few. Navicula salinarum, abundant. 
The scarcity of microscopic life and the total absence of clean-water 
life is paralleled by the chemical condition of the water at this station, 
where the examination of samples showed a total absence of dissolved 
oxygen and the presence of multitudes of bacteria and gas-forming organ- 
isms (see Tables X, XI). 
From the first iron bridge to the Brownfield woods bridge, a distance 
of about a mile and a quarter, the stream is very shallow, less than a foot 
in depth on the average, the water grayish with a sloppy appearance, and 
the odor foul in places, though not as nauseating as below the first bridge. 
Putrescent masses of soft, grayish-black or greenish matter, ranging in size 
from a penny to a platter, may be seen floating down stream, held together 
by algal strands. Brown masses observed on shore resembled human ex- 
crement. The oily appearance of the surface of the water continues and 
oily ma ‘er ascends when the bottom is disturbed. 
From the Brownfield bridge to the third (farmer’s) bridge, a distance 
of about three-quarters of a mile, the conditions are the same as above this 
bridge (Fig. 38). Between the third bridge and the Cottonwoods road 
bridge, a distance of about a mile, the water is very shallow, scarcely 
exceeding six-inches in depth, with gravel or sand bottom. Sludge bars, 
of sand mixed with organic matter, are frequent, in many places occupying 
more than half the width of the stream, the channel, a few inches to a foot 
in depth, meandering over the bottom between these bars (Fig. 40). 
These bars presented a striking appearance, the stones and sand being 
black from the decomposing organic matter, and the foul water algae 
being arranged in long streaks, presenting in combination a striped green 
and black design. The green algae is here very abundant, floating in the 
stream or covering the shores. In places the encrusting material on the 
shore margins is bright yellow. Everywhere along the stream the exposed 
surface of the bottem is black from the decompcsing organic matter, 
which covers all objects and has been baked hard by the hot summer’s 
suo. The vegetation bordering the shore also shows the effect of sewage 
action, being either black in color or having the dried pieces of polluted 
material attached to the lower part of the plants. The same conditions 
prevail from the Cottonwoods road to the Mayview road, a distance of 
about two miles. 
