Seite - 358 - in The Origin of Species

358 ORIGIN OF SPECIES forms are now commonly admitted to be teleostean ; and even some palaeozoic forms have thus been classed by one high authority. If the teleosteans had really appeared suddenly in the northern hemisphere at the commencement of the chalk formation, the fact would have been highly remarkable; but it would not have formed an insuperable difficulty, vmless it could likewise have been shown that at the same period the species were suddenly and simultaneously developed in other quarters of the world. It is almost superfluous to remark that hardly any fossil-fish are known from south of the equator ; and by running through Pictet's Palaeontology it will be seen that very few species are known from several forma- tions in Europe. Some few families of fish now have a con- fined range; the teleostean fishes might formerly have had a similarly confined range, and after having been largely de- veloped in some one sea, have spread widely. Nor have we any right to suppose that the seas of the world have always been so freely open from south to north as they are at pres- ent. Even at this day, if the Malay Archipelago were con- verted into land, the tropical parts of the Indian Ocean would form a large and perfectly enclosed basin, in which any great group of marine animals might be multiplied; and here they would remain confined, until some of the species became adapted to a cooler climate, and were enabled to double the Southern capes of Africa or Australia, and thus reach other and distant seas. From these considerations, from our ignorance of the geol- ogy of other countries beyond the confines of Europe and the United States, and from the revolution in our palaeontological knowledge effected by the discoveries of the last dozen years, it seems to me to be about as rash to dogmatize on the suc- cession of organic forms throughout the world, as it would be for a naturalist to land for five minutes on a barren point in Australia, and then to discuss the number and range of its productions.