The bone-caves in the neighbourhood of the Mediterranean afford most important testimony as to the geographical changes which have taken place, since the animals found in them lived in that region. We will take those of the Iberian peninsula first. _Caves of Gibraltar._ Ossiferous caverns have long been known to occur in the fortified rock of Gibraltar,[243] but were not examined scientifically until the year 1863, when the researches of Captain Brome, Prof. Busk, and Dr. Falconer, proved that pleistocene species were buried in considerable numbers in its cavities and fissures. Of these the most important is the great perpendicular fissure in Windmill Hill, called the Genista cave, which has been traced down to more than a depth of 200 feet. From the upper portion were obtained the polished stone implements, human skulls, and other neolithic remains described in the sixth chapter, p. 204, which prove that Gibraltar was inhabited by the Basques in the neolithic age, while the remains from the lower revealed the presence of a singularly mixed group of animals. The fossil bones have been referred by Prof. Busk and Dr. Falconer to the following species:-- _Lepus cuniculus_, rabbit. _Felis leo_, lion. _F. pardus_, panther. _F. caffer._ _F. pardina_, lynx. _F. serval_, serval. _Ursus ferox_, grizzly bear. _Canis lupus_, wolf. _Equus caballus_, horse. _Rhinoceros hemitœchus._ _Capra ibex_, ibex. _Sus scrofa_, wild-boar. _Cervus elaphus_, red deer. _C. capreolus_, roe. _C. dama_, fallow deer. The spotted hyæna, the serval, and _Felis caffer_, are species now peculiar to Africa, and it is obvious that they could not have found their way into Gibraltar under the present physical conditions of the Mediterranean. Elephants and rhinoceroses could not have lived on so barren and treeless a rock, unless it had overlooked a fertile plain, nor would the carnivora have chosen it for their dens, had it then been cut off from the feeding-grounds of the herbivores. Their presence, therefore, as Dr. Falconer justly remarks, implies the existence of land now sunk beneath the waves, but then extending southwards to join Africa. To the African animals, mentioned above as inhabiting the Iberian peninsula in the pleistocene age, M. Lartet has added the African elephant (_E. Africanus_) and the striped hyæna (_II. striata_), which have been found in a stratum of gravel near Madrid along with flint implements.[244] None of the purely arctic mammalia, such as the reindeer, musk sheep, or woolly rhinoceros, so abundant in France, Germany, and Britain, have been met with south of the Pyrenees. _Bone-caves of Provence and Mentone._