His greatest enemy, however, is man, who so pollutes the streams with sewage and factory refuse that no self-respecting muskrat can live in many of them, and who hunts him for his fur for the making of automobile coats. Yet in the case of my Ponkapoag Pond friends man’s hand for once is for him rather than against. His home there is now a part of the park system and he may be shot or trapped only under penalty of the law. This has been so for some years now and I think it explains the numbers of the winter lodges which are this year greater than ever before. THICK ICE In the winter the pond finds a voice. The great sheet of foot-thick, white ice is like a gigantic disk in a telephone, receiver and transmitter in one, sending and receiving messages between the earth and space. Probably these messages pass equally in summer, only the instruments are so tuned then that our finite ears may not perceive them; for the surface of the pond has its water disk in the summer no less than in winter, but an exquisitely thinner and finer one. Taking to-day my first canoe trip of the year about the edges where the imperative orders of the coming spring have opened clear water for a half-hundred feet, I could not help noticing this thinner disk. The west wind blew keen, but lightly, and had crowded the ice over toward the eastern shore, leaving me free northwest passage in sunny shallows where no ripple disturbed. Every dip of the paddle threw drops of water on the surface, drops that shone like diamonds in the warm sun, but sought, always for a time in vain, to reunite with their kindred water. This invisible barrier held them up and they rolled about without wetting it, just as they might have on a glossy disk of metal, though they finally vanished into it. Like the drops the disk was made up of molecules of water, but the fact that these rested on the very summit of their fellows and between them and the air seemed to change their character and give them a property of impenetrability. It is this disk of water on water that holds up the summer water striders, lean and ferocious-looking insects that skip about on the surface, the tips of their long legs denting it but never being wet. There is a big black land spider that lives on the water’s edge summers, who is husky and heavy, yet will run along the surface, galloping and jumping just as if on a dry and sandy beach and neither falling in nor wetting his feet.