266 PICTURESQUE SKETCHES 



is still correct in a general sense, and expresses, with- 

 out much exaggeration, the real extent of difference 

 in condition, the result, perhaps, a lapse of time 

 greater than is elsewhere indicated. In this -way 

 the secondary period is distinctly cut off from the 

 tertiary. It is scarcely less separated by the fact 

 that in the former we every where find marks of the 

 presence or near vicinity of the sea in all the deposits, 

 even those from fresh water, while, in the newer beds, 

 land animals at once assume the importance which 

 they have ever since retained, having been evidently 

 present in great numbers and variety. 



Confining ourselves, at present, to the principal lo- 

 calities of older tertiary deposits in Europe, we find 

 distinct indications, from the nature of the beds them- 

 selves, that they were deposited with a considerable 

 degree of regularity, and even uniformity, and not in 

 a very short time. The beds are extensive, and con- 

 sisted at first of such rolled pebbles as might have been 

 produced by the rubbing and wearing of the chalk 

 flints on a shingle beach. The rocks were broken 

 into small and similar fragments, rolled until they 

 were perfectly smooth and either round or oval, and 

 thus appear of nearly uniform character throughout 

 widely distant tracts. Whatever, therefore, was the 

 condition of the district now covered by the older 

 tertiary beds of England, France, and Belgium, dur- 

 ing those ages that elapsed between the final depo- 

 sition of the chalk as we now see it, and the deposit 

 of pebble-beds upon its worn surface, the cause that 

 brought into existence these beds seems to have been 

 connected with the re-introduction of a coast-line, 

 and a shallow adjacent sea-bottom. Whether, as is 



