298 Royal Society : — 



animals, hitherto supposed to have been extinct long anterior to the 

 existence of our race. These observations are supposed by some to 

 prove the great antiquity of the human race ; whilst others, equally 

 competent to form an opinion, admit that the intermixture of such 

 remains presents a most perplexing mystery. 



Whatever may be the result of yet unpublished or of future and 

 more extensive observations, it is certainly premature to assign this 

 great antiquity to our race, as long as the occurrence of such mix- 

 tures can be explained by known causes admitted to be still in action. 



Two places have recently been pointed out in which such mixtures 

 are stated to occur : — 1 st, certain localities in France ; 2nd, certain 

 caves in Sicily. The latter have been visited by Dr. Falconer, and 

 as the information respecting them which we at present possess, 

 though small, is yet much more definite than what is known of the 

 French locality, my explanations will chiefly relate to the latter. 



It is stated that one of the Sicilian caves has its sides perforated 

 by marine animals. 



That on penetrating the stalactitical incrustation covering the 

 roof of the cavern, and detaching fragments, it was found to consist 

 of a breccia of bones of animals long extinct, mixed with fragments 

 of flint or stone, bearing evident traces of human art. 



In order to explain these circumstances, it is only necessary to 

 admit the upheaval of the land and the occurrence of torrents. 



Fig. 1. 



\st Period. — Let us suppose two caverns, a lower. A, and an 

 upper, B C, communicating with each other by a long rent or pipe 

 P. This pipe may be supposed of any height, sufficient when filled 

 with water to produce the required force. 



The lower cavern is supposed to be nearly at the level of the sea. 

 Pholades and other marine animals will perforate or attach them- 

 selves to the bottom and sides of the cavern ; and if the sea entirely 

 fill it, the roof too, or at least that portion adjacent to the mouth of 

 the cavern, may be similarly affected. The rocks in which these 

 caverns occur may be of any geological age. 



2nd Period. — By the gradual or quick upheaval of the strata in 

 which these caverns occur, they may become dry. 



