Lastly, it is interesting to note the ever-increasing part taken by American geologists in the advance of this science. There has been through the century a gradual movement of what might be called the center of gravity of geological research westward, until now, at its end, the most productive activity is here in America. This is not due to any superiority of American geologists, but to the superiority of their opportunities. Dana has well said that _America is the type continent of the world_. All geological problems are expressed here with a clearness and a simplicity not found elsewhere. We must add to this the comparative recency of geological study in this rich field. In Europe the simpler and broader problems are already worked out, and all that remain are difficult problems requiring much time. In America, on the contrary, not only are all problems expressed in simpler terms, but many great and broad problems are still awaiting solution. For these reasons the greatest activity in research, and the most rapid advance during the next century, will probably be here in America. "SALAMANDERS" AND "SALAMANDER" CATS. BY NORMAN ROBINSON. In many places in the extreme Southern States, especially in what is locally known as the "piney woods," one of the most notable features is the constantly recurring mounds of yellow sand which everywhere dot and, it must be confessed, disfigure the monotonous landscape. These piles of earth are usually nearly circular in form, fairly symmetrical in contour, from six inches to two feet in diameter, and, save where they have been beaten down by rain or winds or the trampling of cattle, about half as high as they are broad. Often these sand heaps are pretty evenly distributed, sometimes so thickly as to cover at least one fourth of the soil surface. If you ask a native the cause of this singular phenomenon, which you will perhaps at first be disposed to consider a kind of arenaceous eruption which has somehow broken out on the face of Nature, your informant will sententiously reply, "Salamanders!" All this disfigurement is indeed the work of a curious little rodent popularly so named and about the size and color of an ordinary rat. He is never seen above ground if he can possibly help it. He digs innumerable branching underground tunnels at depths varying from one to six feet, and these mounds of sand are simply the "dump heaps" which, in his engineering operations, he finds it necessary to make. [Illustration: "SNAP-SHOT" VIEW OF A LIVE "SALAMANDER."]