The geographical distribution of animals, with a study of the relations ...

—110 DISTRIBUTION OF EXTINCT ANIMALS. Tpart ti.Historic Period.—In tracing back the history of the organicworld we find, even within the limits of the historical period,that some animals have become extinct, while the distribution ofothers has been materially changed. The Rytina of the NorthPacific, the dodo of Mauritius, and the great auk of the NorthAtlantic coasts, have been exterminated almost in our owntimes. The kitchen-middens of Denmark contain remains ofthe capercailzie, the Bos primigenins, and the beaver.The firststill abounds farther north, the second is extinct, and the thirdis becoming so in Europe. The great Irish elk, a huge-antlereddeer, probably existed almost down to historic times.Pleistoceneor Post-Pliocene Period.—We first meet with proofsof important changes in the character of the European fauna,studying the remains found in the caverns of England and France,which have recently been so well explored.inThese cave -remainsare probably all subsequent to the Glacial epoch, and they allcome within the period of man's occupation of the country. Yetwe find clear proofs of two distinct kinds of change in theforms of animal life. First we have a change clearly traceableto a difference of climate. We find such arctic forms asthe rein-deer, the musk-sheep, the glutton, and the lemming,with the mammoth and the woolly rhinoceros of the Siberianice-cliffs, inhabiting this country and even the south of France.This is held to be good proof that a sub-arctic climate prevailedover all Central Europe ; and this climate, together withthe continental condition of Britain, will sufficiently explainsuch a southward range of what are now arcticforms.But together with this change we have another that seems atfirst sight to be in an exactly opposite direction. We meetwith numerous animals which now only inhabit Africa, or SouthEurope, or the warmer parts of Asia. Such are, large felinessome closely related to the lion (Felis spelcca), others of altogetherextinct type (Machairodus) and forming the extreme developmentof the feline race ;—hyaenas ; horses of two or morespecies ;and a hippopotamus. If we go a little further back, tothe remains furnished by the gravels and brick-earths, we stillfind the same association of forms. The reindeer, the glutton,