258 ON THE ORIGIN OF SPECIES 



of the lapse of years. During each of these years, over 

 the whole world, the land and the water has been 

 peopled by hosts of living forms. What an infinite 

 number of generations, which the mind cannot grasp, 

 must have succeeded each other in the long roll of 

 years ! Now turn to our richest geological museums, 

 and what a paltry display we behold ! 



On the poorness of our Palceontological collections. — 

 That our palaeontological collections are very im- 

 perfect, is admitted by every one. The remark of 

 that admirable palaeontologist, the late Edward Forbes, 

 should not be forgotten, namely, that numbers of our 

 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 

 organism wholly soft can be preserved. Shells and 

 bones will decay and disappear when left on the 

 bottom of the sea, where sediment is not accumulat- 

 ing. I believe we are continually taking a most 

 erroneous view, when we tacitly admit to ourselves 

 that sediment is being deposited over nearly the whole 

 bed of the sea, at a rate sufficiently quick to embed 

 and preserve fossil remains. Throughout an enor- 

 mously large proportion of the ocean, the bright blue 

 tint of the Mater bespeaks its purity. The many cases 

 on record of a formation conformably covered, after an 

 enormous interval of time, by another and later forma- 

 tion, 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 or gravel, will 

 when the beds are upraised generally be dissolved by 

 the percolation of rain-water. I suspect that but few 

 of the very many animals which live on the beach 

 between high and low watermark are preserved. For 



