Mr Darwin speaks of a large wolf-like Fox (_Canis antarcticus_) which at the time of his voyage was common to both the Falkland Islands, but absolutely confined to them. He says, "As far as I am aware, there is no other instance in any part of the world, of so small a mass of broken land, distant from a continent, possessing so large an aboriginal quadruped peculiar to itself. Their numbers have rapidly decreased; they are already banished from that half of the island which lies to the eastward of the neck of land between St Salvador Bay and Berkeley Sound. Within a very few years after these islands shall have become regularly settled, in all probability this fox will be classed with the Dodo, as an animal which has perished from the face of the earth."[67] The Musk Ox (_Ovibos moschatus_), a long-haired ruminant, resembling what you would suppose a cross between a bull and a sheep might be,--formerly an inhabitant of Britain with the Elephant and the Hyena, but now found only on the polar margins of North America,--is becoming very scarce; and it is probable that before long its last representative will leave its bones with those of the lamented Franklin and his companions. From the more perishable character of vegetable tissues we have far less data for determining the extinction of plant species; but analogy renders it highly probable that these also have died out, and are dying in a corresponding ratio with animals. I am not aware that a single example can be adduced of a plant that has certainly ceased to exist during the historic era. But Humboldt mentions a very remarkable tree in Mexico, of which it is believed only a single specimen remains in a state of nature. It is the Hand-tree (_Cheirostemon platanoides_), a sterculaceous plant with large plane-like leaves, and with the anthers connected together in such a manner as to resemble a hand or claw rising from the beautiful purplish-red blossoms. "There is in all the Mexican free States only one individual remaining, one single primeval stem of this wonderful genus. It is supposed not to be indigenous, but to have been planted by a king of Toluca about five hundred years ago. I found that the spot where the Arbol de las Manitas stands is 8825 feet above the level of the sea. Why is there only one tree of the kind? Whence did the kings of Toluca obtain the young tree, or the seed? It is equally enigmatical that Montezuma should not have possessed one of these trees in his botanical gardens of Huaxtepec, Chapoltepec, and Iztapalapan, which were used as late as by Philip the Second's physician, Hernandez, and of which gardens traces still remain; and it appears no less striking that the Hand-tree should not have found a place among the drawings of subjects connected with Natural History, which Nezahual Coyotl, king of Tezcuco, caused to be made half a century before the arrival of the Spaniards."