1866.] NATURAL HISTORY SOCIETY. 21 



3. They may have been deposited with the gravel. In this case 

 they belong historically to a very ancient period, though geologi- 

 cally modern ; and at the time when they were so deposited the 

 climate of France must have been more severe than at present, its 

 level different, its surface covered with dense forests, inhabited by 

 several great quadrupeds now extinct, and the River Somme must 

 have been much larger than at present, and must have spread its 

 waters over a wide plain, in which the St. Acheul gravel constitu- 

 ted a bank or point, inundated in times of flood, and perhaps re- 

 sorted to by the aborigines as a place for making canoes. 



4. Before either of the two theories above stated can be finally 

 accepted, much more thorough investigations must be made, and 

 also careful topographical surveys of the whole district. In event 

 of the view last mentioned being sustained, the question of the 

 absolute time required will still be difficult to determine, since the 

 causes of erosion and deposition in operation at the period in ques- 

 tion must have been very dissimilar from those now in action ; and 

 other unknown causes, whether sudden or gradual in their opera- 

 tion, must have intervened to produce the present state of the 

 country. In this case, however, there would be a strong probabi- 

 lity that the Rhinoceros tichorhinus and the Mammoth had conti- 

 nued to exist in Europe down to the period of the implement 

 making. 



It is much to be desired that a series of systematic excavations 

 in these gravels, and a geological and topographical survey of the 

 whole basin of the Somme should be undertaken by some scientific 

 body in France or England, as it may require many years to 

 enable individual explorers to obtain the data required to settle the 

 questions that have been raised in connection with these deposits. 



The society's thanks were voted to Dr. Gibb and to Dr. Dawson, 

 and the meeting thereafter adjourned. 



The fifth monthly meeting of the Society was held Monday 

 evening, January 29 ; The President in the chair. 



NEW MEMBER. 



Mr. Alexander Agassiz, of Cambridge, U. S., was elected a 

 corresponding member. 



PROCEEDINGS. 



It was resolved to hold the Annual Conversazione on Thursday 

 evening, March 1, and a committee was appointed to make the ne- 

 cessary arrangements. 



