July 5, 1895.] 



SCIENCE. 



London in 1892,f the author gave the evi- 

 dence deduced from personal observation of 

 the submergence of the south of England not 

 less than 1000 feet between the glacial or 

 post-glacial and recent or neolithic period 

 and proposed the term ' rubble drift ' for the 

 peculiar superficial drift then deposited. In 

 the memoir under notice Professor Prestwich 

 cites the phenomena he relies on as proofs 

 of this submergence in England and traces 

 their extension over large continental areas. 



The author describes the ' rubble drift ' 

 as sometimes simulating other drift deposits, 

 but maintains that it cannot be included 

 with them on account of its varied physical 

 distribution and faunal divergences. It is 

 distinguished chiefly by the absence of all 

 marine and fluviatile shells; the included 

 remains are those of land animals and land 

 shells alone, and of land plants derived 

 from a land surface only. He points out 

 that mammalian bones from the ordinarjr 

 Quaternarj^ deposits are very fragmentary, 

 characterized by the absence of wear and 

 also devoid of traces of gnawing in con- 

 tradistinction from those of the caves, 'which 

 have commonly been gnawed by predaceous 

 animals,' and from those of the fluviatile 

 deposits, which are usually worn. 



The detritus of the ' rubble drift ' is always 

 of local origin, and as a rule unstratified. 

 Professor Prestwich considers therefore that 

 it can only be accounted for by an upheaval 

 of a submerged land surface after wide- 

 spread submergence, the consequent diver- 

 gent effluent currents of water sweeping 

 the detritus of the submerged surface from 

 the higher to the lower levels. " A body 

 of water 1,000 feet deep forms an engine of 

 enormous power." He maintains that all 

 the phenomena of this ' rubble drift ' are 

 explicable only upon this hypothesis. 



The 'rubble di'ift,' widely, if sparsely, 

 spread over the Southeast of England, can 



t Quarterly Journal Geological Society of London, 

 vol. 48, p. 263. 1892. 



be traced over much of western Europe 

 and the Mediterranean coasts. It has been 

 personally observed by him in parts of 

 France and Italy. Other geologists have 

 noted similar phenomena elsewhere without 

 attempting to account for their origin. Pro- 

 fessor Prestwich holds it to be impossible 

 that the confusing accumulations of super- 

 ficial debris lying on the surface of the land 

 without apparent order or stratification 

 could all be due to the transient action of 

 water, and that glacial, fluviatile and me- 

 teoric action fail to account for all the 

 phenomena. To the residue he applies the 

 name of ' rubble drift,' as distinguished 

 from the term diluvium, which is still var- 

 iously employed on the continent to denote 

 fluviatile, sub-jerial and other drift beds, 

 and does not include the more important 

 phases of the ' rubble drift ' period, " which 

 marks the last stage of a long series of 

 earth movements of variable intensitj^ and 

 duration." "Whilst admitting the per- 

 manence of the laws of nature, it is impos- 

 sible to suppose that at all former periods 

 the effects produced by these laws, though 

 not equal in kind, were equal in degree." 



The absence of marine sediments in the 

 ' rubble drift ' is not to be regarded as fatal 

 to his theory if the submergence were of 

 short duration, which would also militate 

 against the migration and establishment of 

 a marine fauna on the submerged area. 

 All the component materials of the ' rubble 

 drift ' are of local origin. It includes re- 

 mains of a land fauna alone, the mamma- 

 lian bones are ungnawn yet sharply frac- 

 tured. The submergence hypothesis he 

 includes not only ' meets the requirements 

 of each particular case, but shows them all 

 to be concordant, and such as would pertain 

 to one common and general cause.' 



Professor Prestwich thus proceeds to re- 

 state his long-held convictions that Croll's 

 estimate of the lapse of 80,000 years since 

 the close of the glacial period is not sup- 



