274 LECTURE X. 



Thickness iu metres. 



1. Vegetable earth ... - - 0-30 



2. Grey undisturbed sand, with broken flints - - 0-70 



3. Yellow argillaceous sand, mixed with large and little rolled 



flints, below which is a bed of grey sand without flints - 1-50 



4. Yellow ferruginous sand, mixed with less thick but more 



rolled flints, below which is a bed of less yellow sand. 

 In this bed Boucher de Perthes found fragments of a 

 tooth of the Mammoth, and some flint hatchets - 1'70 



5. Black argDlo-feiiTiginous sand, colouring and sticking to 



the hand ; small i^ebbles, more rolled than in the higher 

 beds. In this bed were found flint hatchets, and the hu- 

 man jaw. a. Marks the spot where Quatrefages found two 

 flint hatchets in the presence of the Congress. 6. The 

 spot where Boucher de Perthes found a flint hatchet : 

 and c. where he found the jaw, March 28, 1863. d. Is the 

 spot where Dr. Falconer found another hatchet, April 14, 

 in the presence of the Congress ... 0'50 



Thickness of the alluvium - - 4-70 

 6. A bed of chalk with an irregular surface. 



The objections raised by Elie de Beaumont^ Perpetual secre- 

 tary of the Frencli Academy^ deserve some special notice ; in 

 order to obviate misapprebension^ I sball state tbem nearly in 

 his own words : " I am of opinion/' says this geologist^ " that 

 the alluvial deposits excavated from the gravel pit at Moulin- 

 Quignon do not belong to the diluvium proper. 



" In my opinion this apparent diluvial formation belongs to 



such deposits as I have formerly called alluvium 



These formations are synchronous with the formation of peat, 

 and may, like it, contain human bones and the products of 

 human industry ; but such deposits which represent a kind 

 of post diluvium, and are formed by detached fragments, 

 transported by atmospheric influences, thunderstorms, snow, 

 frost, and rain, may contain what the small diluvial deposits 

 collected on the surface or the fissures of the rocks contain, 

 namely, bones and teeth of elephants, etc., which belong to such 

 bodies as are less apt to be destroyed by atmospheric influ- 

 ences or transportation. 



^' The men and elephants, the bones of which are found in 

 such deposits, need not, therefore, have been contempora- 



