106 Chronicles of Science. [Jan., 



gravel-beds being so much above the existing river-channels, combined 

 with the occurrence in them of perfect and uninjured land and fresh- 

 water shells, and the remains (sometimes entire) of land-animals of 

 various ages, points to a former condition of things when such levels 

 constituted the lowest ground over which the waters passed. 



Mr. Prestwich then states that there is "evidence of great trans- 

 porting power " in " the size and quantity of the debris," and of 

 " floods of extraordinary magnitude," in the fact of " fine silt, with 

 'land-shells, covering all the different gravel-beds." Thus he believes 

 the gravel-beds were accumulated and the valleys excavated by river- 

 action of much greater intensity than that now in operation, " period- 

 ical floods imparting a torrential character to the rivers ;" moreover, 

 he considers that " river-action peculiar to each valley commenced 

 with the high-level gravels," and that " the mass of debris and the 

 large blocks present in the beds indicate the action of a large volume 

 of water, and of ice-transport." 



The author also connects the loess with both series of valley- 

 gravels and with the existing river-valleys, regarding it as contempo- 

 raneous with the associated gravel-beds, and as representing the fine 

 silt deposited from flood waters in such parts of the channel as are in 

 a state of comparative repose, namely, " the lee side of the hills, 

 lateral valleys, and plains, and any local depressions or hollows," while 

 coarser material, represented by the present gravels, was left in the 

 more central portions. He therefore concludes that, as in the case of 

 the associated gravels, the higher deposits of loess were formed before 

 the excavation of the valleys, and that those on the lower terraces are 

 of later date. 



Mr. Prestwich discusses also the probable antiquity of the deposits 

 containing the flint implements, and he shows that though, geologically, 

 they are posterior to the boulder clay, and consequently to the great 

 extension of the European glaciers, yet that, chronologically, measur- 

 ing their age by such natural chronometers as the excavation of the 

 river-valleys, they must be so extremely ancient that all attempts to 

 compute their age in hundreds of thousands of years are now, and 

 probably always will be, utterly futile. 



The ' Geological Magazine ' continues to sustain its excellent 

 character, the last four numbers having contained many important 

 original papers, and a great number of abstracts and notices of in- 

 teresting British and Foreign publications As might be expected 

 some of the original articles refer to phenomena familiar to most 

 geological students ; such, for instance, is Mr. S. P. Woodward's 

 article " On Banded Flints," in which the author strives to show that the 

 coloured bands have been produced by infiltration, as taught by the 

 late Professor Henslow. On the other hand, many of the papers are 

 of a very recondite nature, but are nevertheless readable and interest- 

 ing : such are the papers by Dr. Duncan and Professor Rupert Jones 

 " On the Miocene Beds of the West Indian Islands ; " Dr. Bigsby's 

 " Description of the Laurentian Formation," &c. Mr. S. P. Woodward's 

 paper " On Plicatula sigillina " is very short, good, and exactly suited to 

 the Magazine in which it appears ; but some other papers, consisting 



