L Évolution souterraine

IN France, the fascinating study of caverns—or, as it is now the fashion to call it, spelseology—has risen greatly in popular favour during the last twenty years, mainly through the energy and enthusiasm M. Martel, one of the editors of La Nature. The scope of spelaeology, in the course of its recent development, has become gradually enlarged until it now touches at one point or another almost the entire circle of the sciences. The work before us, which, forms a volume of Dr. Gustave Le Bon\u27s “Bibliotheque de Philosophic scientifique,” extends, however, beyond the mere study of caves, though this forms its main theme. From caverns the author passes to the general phenomena of the underground world, and seeks to show how their study has a bearing on nearly all branches of knowledge, especially on the doctrine of evolution. The range of the work consequently comes to be extremely wide. Where the programme set before the writer is so ambitious, no reasonable reader can expect to find it worked out with thoroughness. Brevity often becomes imperative. The wonder is not that many of the subjects are touched with only a light hand; the wonder is rather that it has been found possible to crowd so much into a volume of such limited size