course thoroughly wet, and, humanly speaking, uncomfortable, though the creature could breathe in it. But it is plain that the muskrat cannot be subject to the toothache. I have no doubt this was made and used last winter, for the grass was as fresh as that in the meadow (except that it was pulled up), and the sand which had been taken out lay partly in a flattened heap in the meadow, and no grass had sprung up through it. In the course of the above examination I made a very interesting discovery. When I turned up the thin sod from over the damp cavity of the nest, I was surprised to see at this hour of a pleasant day what I took to be beautiful frost crystals of a rare form, frost bodkins I was in haste to name them, for around the fine white roots of the grass, apparently herds grass, which were from one to two or more inches long, reaching downward into the dark, damp cavern (though the grass blades had scarcely made so much growth above; indeed the growth was scarcely visible there), appeared to be lingering still into the middle of this warm afternoon, rare and beautiful frost crystals exactly in the form of a bodkin, about one sixth of an inch wide at base, and tapering evenly to the lower end. Sometimes the upper part of the core was naked for half an inch, which gave them a slight resem-
