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Bulletin Wisconsin Natural History Society. [Vol. 10, Nos. 3-4. 
intestinal contents (ib., 158), “Their digestive tube is often filled 
with a brown granular material consisting, as nearly as can be 
made out with the microscope, of decomposed organic matter con¬ 
taining great numbers of bacteria and a good many empty 
frustules of diatoms. In one example was found the fragments of 
an insect,” and further discussion follows. Higginson (1867, 176) 
says they ate the chlorophyllous tissue of the grass blades bending 
into the water in an earthen garden pot. Were they starved to 
this through lack of algae or through desire for a varied diet? 
It is this feeding on organic debris and sediment accumulating 
at the bottom of a body of water (Folsom, 1909, 185) which brings 
them most often into stagnant water (Kirby, 1892, 221) and 
people do well to keep ornamental earthen water pots of the garden 
(Higginson 1867, 174), rain-water barrels and horse-troughs 
cleaned if they do not want to see, lying at the bottom, a vision 
of tiny red threads (Craigin, 1899, 279). Here they make larval 
cases of silk and mud or decomposing leaves (Howard, 1908, no; 
Osborn, 1896a, 30; Reaumur, 1737, 179; and 1740, 29-39, 5 T 
being the earliest account of their metamorphosis) ; or, in the case 
of those used by fish, a large deep-water “red larva” species in 
a loose gelatinous case (Needham, 1903, 208-9; Osborn, 1896a, 
406), showing that Westwood may have meant another species 
than plumosus which he was reviewing when he said (1840, 
516-7), “These larvae assemble in a mass, and form tortuous [ ?] 
tubes which unitedly compose an irregular mass at the bottom of 
the water, formed of particles of decomposed leaves.” Garman 
(1896, 158), summarizing several Mississippi species, says that 
they “commonly live at the bottom, under stones, and rubbish, 
where they construct galleries of agglutinated sand in which num¬ 
bers live together.They are extremely common and may 
be captured at night in surface nets literally by the pint.” This 
points to the peculiarly nocturnal frequency of the following habit 
added by Miall (1903, 123), “Now and then they leave their bur¬ 
rows and swim through the water with a lashing movement, twist¬ 
ing themselves into figures of 8” (So Higginson, 1867, 174). 
“Occasionally they rise to the surface, as if to renew their supply 
of oxygen. They are careless about finding their way back to their 
burrows, for in a short time they can glue together enough fresh 
