IN the autumn of 1878 I was salmon fishing in the River Spey, a few miles from its mouth, where the stream was broad, strong, and deep—when just beyond the end of my line I perceived a squirrel being carried down, but swimming higher out of the water than is usual with most animals. Its death by drowning seemed inevitable, as the opposite bank was a high, perpendicular cliff of Old Red Sandstone, where even a squirrel could hardly land. However it swam gallantly on, heading straight across the stream, and finally, after being swept down a long distance, emerged on the other side, where a burn intersected the rock, and fir-trees grew down to the water's edge. The left bank, where the squirrel must have entered the river, was low and shelving, and it selected a spot, accidentally or otherwise, whence the current carried it opposite to an easy landing-place on the right bank.