58 THE POORNESS OF OUR [Chap. X. 



On the Poorness of Palceontological Collections. 



Now let us turn to our richest geological museums, 

 and what a paltry display we behold! That our col- 

 lections are imperfect is admitted by every one. The 

 remark of that admirable palajontologist, Edward 

 Forbes, should never be forgotten, namely, that very 

 many fossil species are known and named from single 

 and often broken specimens, or from a few specimens 

 collected on some one spot. Only a small portion of 

 the surface of the earth has been geologically explored, 

 and no part with sufficient care, as the important dis. 

 coveries made every year in Europe prove. No organ 

 ism wholly soft can be preserved. Shells and bones de- 

 cay and disappear when left on the bottom of the sea, 

 where sediment is not accumulating. We probably take 

 a quite erroneous view, when we assume that sediment ia 

 being deposited over nearly the whole bed of the sea^ at 

 a rate sufficiently quick to embed and preserve fossil re- 

 mains. Throughout an enormously large proportion of 

 the ocean, the bright blue tint of the water bespeaks its 

 purity. The many cases on record of a formation con- 

 formably covered, after an immense interval of time, by 

 another and later formation, without the underlying 

 bed having suffered in the interval any wear and tear, 

 seem explicable only on the view of the bottom of the 

 sea not rarely lying for ages in an unaltered condition. 

 The remains which do become embedded, if in sand oi 

 gravel, will, when the beds are upraised, generally be 

 dissolved by the percolation of rain-water charged -nith 

 carbonic acid. Some of the many kinds of animals 

 which live on the beach between high and low water 

 mark seem to be rarely preserved. For instance, the 



