radiation at night, from the surrounding ground and herbage. I am inclined to believe in this latter view; firstly, because when worms were kept in pots in a room with a fire, in which case cold air could not enter the burrows, they plugged them up in a slovenly manner; and secondarily, because they often coat the upper part of their burrows with leaves, apparently to prevent their bodies from coming into close contact with the cold damp earth. But the plugging-up process may perhaps serve for all the above purposes.
Whatever the motive may be, it appears that worms much dislike leaving the mouths of their burrows open. Nevertheless they will reopen them at night, whether or not they can afterwards close them. Numerous open burrows may be seen on recently-dug ground, for in this case the worms eject their castings in cavities left in the ground, or in the old burrows, instead of piling them over the mouths of their burrows, and they cannot collect objects on the surface by which the mouths might he protected. So again on a recently disinterred pavement of a Roman villa at Abinger (hereafter to be described)
