One of these cases illustrates the variations of animals under domestication, the particular specimens selected being chiefly the familiar pigeon, in its various forms, and the jungle-fowl with its multiform domesticated descendants. Another case illustrates very strikingly the subject of protective coloration of animals. Two companion cases are shown, each occupied by specimens of the same species of birds and animals--in one case in their summer plumage and pelage and in the other clad in the garb of winter. The surroundings in the case have, of course, been carefully prepared to represent the true environments of the creatures at the appropriate seasons. The particular birds and animals exhibited are the willow-grouse, the weasel, and a large species of hare. All of these, in their summer garb, have a brown color, which harmonizes marvellously with their surroundings, while in winter they are pure white, to match the snow that for some months covers the ground in their habitat. The other cases of this interesting exhibit show a large variety of birds and animals under conditions of somewhat abnormal variation, in the one case of albinism and the other of melanism. These cases are, for the casual visitor, perhaps the most striking of all, although, of course, they teach no such comprehensive lessons as the other exhibits just referred to. The second of the novel exhibits of the museum to which I wish to refer is to be found in a series of alcoves close beside the central cases in the main hallway. Each of these alcoves is devoted to a class of animals--one to mammals, one to birds, one to fishes, and so on. In each case very beautiful sets of specimens have been prepared, illustrating the anatomy and physiology of the group of animals in question. Here one may see, for example, in the alcove devoted to birds, specimens showing not only details of the skeleton and muscular system, but the more striking examples of variation of form of such members as the bill, legs, wings, and tails. Here are preparations also illustrating, very strikingly, the vocal apparatus of birds. Here, again, are finely prepared wings, in which the various sets of feathers have been outlined with different-colored pigments, so that the student can name them at a glance. In fact, every essential feature of the anatomy of the bird may be studied here as in no other collection that I know of. And the same is true of each of the other grand divisions of the animal kingdom. This exhibit alone gives an opportunity for the student of natural history that is invaluable. It is quite clear to any one who has seen it that every natural history museum must prepare a similar educational exhibit before it can claim to do full justice to its patrons.