OF ORGANIC NATURE 37 



is being thus formed. You may see in the galleries of the 

 Museum upstairs specimens of limestones in which such 

 fossil remains of existing animals are imbedded. There 

 are some specimens in which turtles' eggs have been 

 imbedded in calcareous sand, and before the sun had hatched 

 the young turtles, they became covered over with calcareous 

 mud, and thus have been preserved and fossilized. 



Not only does this process of imbedding and fossilization 

 occur with marine and other aquatic animals and plants, 

 but it affects those land animals and plants which are 

 drifted away to sea, or become buried in bogs or morasses ; 

 and the animals which have been trodden down by theu: 

 fellows and crushed in the mud at the river's bank, as the 

 herd have come to drink. In any of these cases, the 

 organisms may be crushed or be mutilated, before or 

 after putrefaction, in such a manner that perhaps only a 

 part will be left in the form in which it reaches us. It 

 is, indeed, a most remarkable fact, that it is quite an 

 exceptional case to find a skeleton of any one of all the 

 thousands of wild land animals that we know are constantly 

 being killed, or dying in the course of nature : they are 

 preyed on and devoured by other animals or die in places 

 where their bodies are not afterwards protected by mud. 

 There are other animals existing in the sea, the shells of 

 which form exceedingly large deposits. You are probably 

 aware that before the attempt was made to lay the Atlantic 

 telegraphic cable, the Government employed vessels in 

 making a series of very careful observations and soundings 

 of the bottom of the Atlantic ; and although, as we must 

 all regret, up to the present time that project has not 

 succeeded, we have the satisfaction of knowing that it 

 yielded some most remarkable, results to science. The 

 Atlantic Ocean had to be sounded right across, to depths 

 of several miles in some places, and the nature of its bottom 

 was carefully ascertained. Well, now, a space of about 

 1,000 miles wide from east to west, and I do not exactly 

 know how many from north to south, but at any rate 600 

 or 700 miles, was carefully examined, and it was found 

 that over the whole of that immense area an excessively 

 fine chalky mud is being deposited ; and this deposit is 

 entirely made up of animals whose hard parts are deposited 

 in this part of the ocean, and are doubtless gradually 

 acquiring solidity and becoming metamorphosed into a 

 chalky limestone. Thus, you see, it is quite possible 



