Earth-Worms tn History. 67 
be not mere excavations, but may be compared with tunnels 
lined with cement. Those which run far down into the 
ground generally, or at least frequently, terminate in little 
chambers, where one or several worms pass the winter rolled 
up into a ball. Small pebbles and seeds as large as grains 
of mustard are carried down from the surface by being swal- 
lowed or within the mouths of worms, as well as bits of glass 
and tile, whose only use in their winter-quarters seems to be 
the prevention of their closely coiled-up bodies from coming 
into contiguity with the surrounding cold soil, for such con- 
tact would perhaps interfere with their respiration, which is 
effected by the skin alone. 
After swallowing earth, whether for making its burrow or 
for food, the earth-worm soon comes to the surface to empty 
its body. The rejected matter is thoroughly mixed with the 
intestinal secretions, and is thus rendered viscid. After be- 
coming dried, it sets hard. When in a very liquid state the 
earth is thrown out in little spurts, and when not so liquid 
by a slow peristaltic movement of the intestine. It is not 
cast indifferently on any side, but first on one and then 
on another, the tail being used almost like a trowel. The 
little heap being formed the worm seemingly avoids, for the 
sake of safety, the use of its tail, the earthy matter being 
forced up through the previously deposited soft mass. The 
mouth of the same burrow is used for this purpose for a 
considerable time. When a worm comes to the surface to 
eject earth, the tail protrudes, but when it collects leaves its 
head must protrude, and thus worms must have the power 
of performing the difficult feat, as it seems to us, of turning 
round in their closely-fitting burrows. Worms do not always 
eject their castings upon the surface of the ground, for when 
burrowing in newly turned-up earth, or between the stems 
of banked-up plants, they deposit their castings in such 
places, and even hollows beneath large stems lying on the 
surface of the ground are filled up with their ejections. Old 
burrows collapse in time. The fine earth voided by worms, 
