CONCLUSIONS. 211 



great stag, the skeleton and horns of which have been found 

 buried in the peat-bogs of Ireland. There are also many 

 species of animals whose numbers are daily diminishing, 

 and whose extinction may be foreseen ; as the Canada deer, 

 ( Wapiti,) the Ibex of the Alps, the Lammergeyer, the 

 bison, the beaver, the wild turkey, &c. 



448. Other causes may also contribute towards dispersing 

 animals beyond their natural limits. Thus, the sea-weeds 

 are carried about by marine currents, and are- frequently 

 met with far from shore, thronged with little crustaceans, 

 'which are in this manner transported to great distances from 

 the place of their birth. The drift wood which the Gulf 

 Stream floats from the Gulf of Mexico even to the western 

 shores of Europe, is frequently perforated by the larvaB of 

 insects, and may, probably, serve as depositories for the eggs 

 of fishes, Crustacea, and mollusks. It is possible, also, that 

 aquatic birds may contribute in some measure to the diffu- 

 sion of some species of fishes and mollusks, either by the 

 eggs becoming attached to their feet, or by means of those 

 which they evacuate undigested, after having transported 

 them to considerable distances. Still, all these circum- 

 stances exercise but a very feeble influence upon the dis- 

 tribution of species in general ; and each country, none the 

 less, preserves its peculiar physiognomy, so far as its animals 

 are concerned. 



449. There is only one way to account for the distribu- 

 tion of animals as we find them, namely, to. suppose that 

 they are autochthonal, that is to say, that they originated 

 like plants, on the soil where they are found. In order to 

 explain the particular distribution of many animals, we are 

 even led to admit that they must have been created at 

 several points of the same zone ; an inference which we 

 must make from the distribution of aquatic animals, especial- 

 ly that of Fishes. If we examine the fishes of the different 



