Three sciences have of late years been advanced by the explorations of caves: paleontology; prehistory, or research among the remains of primitive men and their industries; and zoölogy, or the study of living beings. The animals of caverns--crustaceans, insects, batrachians, and fishes--constitute a special fauna, which has been for fifty years a subject of study to naturalists of various nations, and to the anatomy of which M. Armand Viré, of the Natural History Museum of Paris, has been giving special attention for five years past. There are other sciences the study of which in connection with caves, while capable of yielding valuable fruits, has been too long neglected: geology, for their origin and formation; mineralogy, for their relations to metallic veins; meteorology, for thermometrical and barometrical variations and the formation of carbonic acid; terrestrial physics, for the experiments on gravity that might be carried on in deep vertical pits, supplementing the observations of Foucault in the Pantheon at Paris, and Airy in the English mines; hydrology, which has hardly yet perceived that caves are predominantly great laboratories of springs; agriculture, which might transform them into reservoirs for times of drought or storage basins in case of flood; and public hygiene, which is just beginning to discover that they may harbor in their fissures hitherto unsuspected causes of contamination of the water of the springs that issue from them. The number and importance of these new problems that have arisen from the recent extension of underground investigations seem fully to justify the specialization of the science of caves--another creation of the Speleological Society, now four years old. This special interest in the science of caves began about fifteen years ago, when, in 1883, three members of the Austro-German Alpine Club--Herren Harske, Marinitsch, and Müller--resumed in the limestone plateaus of Istria and Carniola called the Karst, explorations which had been actively and profitably carried on in the middle of the century, from 1850 to 1857, by Dr. Adolf Schmidt, whose discoveries in the caves of Adelsberg, Planina, and St. Canzion won him a membership in the Vienna Academy of Sciences. Their efforts and those of Herr F. Kraus, who died last year, had the result of interesting the Austrian Government in the subject; and since 1886 various engineers have been commissioned by the Minister of Agriculture to make official explorations and construct economical works in the caves and underground rivers of Istria, Carniola, and Herzegovina. Credits are granted every year for enterprises which prove to be more useful than would at first be thought.