316 PALAEONTOLOGY. 



convert themselves into extraneous fossils by forming either a mould 

 or cast, or both, of the organic remains either at the bottom of the 

 sea, or which are carried into it. Thus the sea has both the fos- 

 silizing materials and the bodies to be fossilized. The sea gives life, 

 and of coiu'se contains a much greater number of animals than the 



same surface of the land does Such are constantly dying, 



and such parts of them as are not perishable, such as the earth of 

 bones and shells, will, by losing the a nim al part, by time, become 

 what we may call a ' Fossil : ' and others, from being in water impreg- 

 nated with such materials as are capable of imbedding their substance, 

 or filling their cavities with such matter, will also be considered as 

 'fossil'." — P. xxxvi. 



" "We may observe that the amphibia, and such as inhabit both the sea 

 and land, as all of the Phoca-tribe, white bear, &c, likewise sea-fowl, par- 

 take of the before-mentioned mode of fossilization, by dying in the sea ; 

 for wherever there has been a shore, there we shall find the amphibia ; 

 as also many of the fowl-tribe, called sea-fowl, which feed in the water, 

 which may die in the sea near the shore, or be brought down in the 

 rivers, will be carried into the sea, and be fossilized according to the 

 fore-mentioned method, and will be found along with the sea productions. 

 But they will also partake of the second situation, as in large valleys 

 leading to the sea, which were formerly arms of the sea or inlets, which 

 are to be considered as having been moving shores, as the sea gradually 

 leaves the land, leaving materials it had robbed higher land of, raising 

 the bottom, or forming a new surface, lessening the depth of water at 

 these places, which renders it slower and slower in its motion, as before 

 described, at last becoming a river. Such new land will bury in it such 

 productions, whether of sea or land, but most of those common to both, 

 as shall either die in it, or being brought into it, constituting chiefly such 

 animals that inhabit both land and water, as also amphibia, with land- 

 animals that came there, or vegetables that were brought there, making 

 a heterogeneous mixture. And I believe it may be observed in general, 

 that the fossil bones of land-animals or birds are commonly found in 

 such deposited materials, as gravel, sand, clay, <fcc." — P. xxxvii. 



"But the preservation of vegetables and land- animals is most probably 

 not confined to such situations alone. A change in the situation of the 

 sea most probably has been a cause in the production of such fossils, 

 which constitutes a third situation of the production of fossils. There- 

 fore, to preserve vegetables, bones of land-animals, and many birds, one 

 of two circumstances must have taken place : first, a change of the 

 situation of the sea upon the land where such productions are. But in 

 [regard to] what may be called ' land-birds,' there will be a few of 



