Chap. IX. PALEONTOLOGICAL COLLECTIONS. 273 



comprehend what tlio firrures 00,000,000 really imply ; and 

 during this, or perhaps a lonfrcr roll of years, the land and the 

 waters have everywhere teemed with livinj^ creatures, all ex- 

 posed to the struggle for life and undergoing change. 



On the Poorness of oitr Paleontological Collections. 



Now let us turn to our richest geological museums, and 

 what a paltry display we behold ! That our collections arc 

 very imperfect is admitted by every one. The remark of that 

 admira1:)lc paleontologist, Edward Forbes, should not be for- 

 gotten, 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 discoveries made 

 eVery year in Europe prove. No organism wholly soft can be 

 preserved. Shells and bones Avill decay and disappear when 

 left on the bottom of the sea, where sediment is not accumu- 

 lating. I believe we often take an 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 

 enormously large proportion of the ocean, the bright blue tint 

 of the water bespeaks its purity. The many cases on record 

 of a formation conformably covered, after an immense interval 

 of time, by another and later formation, Avithout tlic underly- 

 ing bed having suffered in the interval any wear and tear, seem 

 explicable only on the view of the l)ottom of the sea not rarely 

 lying for ages in an unaltered condition. The remains Avhich 

 do become embedded, if in sand or gravel, will when the beds 

 are upraised generally be dissolved by the percolation of rain- 

 water chargetl with carbonic acid. Some of the many kinds 

 of animals which live on the beach between high and low 

 water mark seem to be rarely jireserved. For instance, the 

 several species of the Chthamalin;!:? (a sub-family of sessile 

 cirripcdes) coat the rocks all over the world in infinite 

 numbers: they are all slridly littoral, with the exception of a 

 single Medit(;rranean species, which inhabits deep water, and 

 this has been f(jund fossil in Sicily, whereas not one other 

 species has hitherto been found in any tertiary formation : yet 

 it is not known that the genus Chthamalus existeil during the 

 T^halk period. Lastly, many great deposits requiring a vast 



