188 



THE GEOLOGIST. 



caves. Referrring to his late exploration of Brixham Cave in 1858, the 

 attention which the well-certified discovery of flint implements in un- 

 doubted association with the remains of extinct mammalia and of reindeer 

 attracted amongst geologists was remarked upon. The speaker visited 

 the cave in company with Mr. Pengelly, and was much struck with the 

 force of the evidence, though, for various reasons, he considered that cave 

 evidence alone was not sufficient. Urged by Dr. Falconer to go and exa- 

 mine the geological evidence respecting the flint implements in the valley 

 of the Somme, he afterwards paid his long-intended visit to Abbeville 

 (where he, on the very first day, was fortunate enough to find three 

 worked flints at Menchecourt.) He was joined, on the next day, at 

 Amiens, by his friend Mr. John Evans. The geological evidence, and the 

 character of the flint implements, satisfied them both that here again was 

 an undoubted case of . contemporaneny of the works of man with the 

 remains of the extinct mammalia. All the author has since seen on many 

 subsequent visits to the Somme valley, sometimes alone, but more fre- 

 quently in company with other geologists, has tended to confirm his first 

 opinion. He then proceeded to notice some of the phenomena he had 

 seen, and to give his conclusions respecting them. He had intended 

 to have described the several localities in France and England at which 

 flint implements had been found, but found that time would not allow his 

 going beyond Amiens. This was the less important, as Mr. Lubbock had 

 so recently given an able account in the same room of most of these 

 places ; and his auditors were probably most of them acquainted with the 

 more general account given by Sir Charles Lyell in his recent work on the 

 ' Antiquity of Man.' 



Mr. Prestwich then went on to describe the remarkable discovery of 

 M. Boucher de Perthes, and how much honour and credit were due to 

 him for his untiring perseverance, in face of general discouragement, for 

 a period of twenty years, and for twelve years after the publication of his 

 elaborate work, ' Antiquites Celtiques et Antediluviennes.' Incited ' by 

 this work, Dr. Higollof, an antiquary of Amiens, discovered flint imple- 

 ments in great numbers near that town ; but his careful memoir on the 

 subject, although it attracted the momentary attention of some French 

 geologists, was allowed to drop comparatively unnoticed. Geologists ad- 

 mitted the antiquity of the beds, and antiquaries admitted the workman- 

 ship of the implements ; but neither would own to a conjoint interest and 

 belief in them. 



Before entering upon the details of the sections, Mr. Prestwicb. pro- 

 ceeded to make a few remarks upon the conditions under which the flint- 

 implement-bcaring beds were found, and how their importance and the 

 time they represent were to be judged of. He observed that sea-formed 

 deposits afforded massive and tangible monuments of the length of time 

 required for their accumulation. But on land time passes, and builds no 

 such monuments of its duration. The sand and shingle beds of a rapid 

 . river would be little, if at all, thicker now than a thousand years ago, for, 

 instead of accumulating in the channel of that river, they are incessantly 

 removed, and carried eventually out to sea, where they contribute to the 

 formation of the great sedimentary deposits constantly going on there. 

 The time represented by river deposits (apart from the recent silty alluvia) 

 is not therefore to be measured by their thickness ; and we must not at- 

 tach the less importance to the beds containing the flint implements, be- 

 cause, being formed by river action, they are necessarily small, fragmen- 

 tary, and superficial. But while in the sea the ac^ 1 c — 



