380 GEOLOGICAL CONTEMPORANEITY 



fossils, and hence no living being could have existed ft! 

 their epoch. 



To this there are two replies : the first, that the observa- 

 tional basis of the assertion that the lowest rocks are 

 nowhere fossiliferous is an amazingly small one, seeing 

 how very small an area, in comparison to that of the whole 

 world, has yet been fully searched ; the second, that the 

 argument is good for nothing unless the unfossiliferous 

 rocks in question were not only contemporaneous in the 

 geological sense, but synchronous in the chronological sense. 

 To use the alibi illustration again. If a man wishes to 

 prove he was in neither of two places, A and B, on a given 

 day, his witnesses for each place must be prepared to 

 answer for the whole day. If they can only prove that 

 he was not at A in the morning, and not at B in the afternoon, 

 the evidence of his absence from both is nil, because he 

 might have been at B in the morning and at A in the 

 afternoon. 



Thus everything depends upon the validity of the second 

 assumption. And we must proceed to inquire what is the 

 real meaning of the word " contemporaneous " as employed 

 by geologists. To this end a concrete example may be 

 taken. 



The Lias of England and the Lias of Germany, the 

 Cretaceous rocks of Britain and the Cretaceous rocks of 

 Southern India, are termed by geologists " contemporane- 

 ous " formations ; but whenever any thoughtful geologist 

 is asked whether he means to say that they were deposited 

 synchronously, he says, " No, only within the same 

 great epoch." And if, in pursuing the inquiry, he is asked 

 what may be the approximate value in time of a " great 

 epoch " whether it means a hundred years, or a thousand, 

 or a million, or ten million years his reply is, " I cannot 

 tell." 



If the further question be put, whether physical geology 

 is in possession of any method by which the actual synchrony 

 (or the reverse) of any two distant deposits can be ascer- 

 tained, no such method can be heard of ; it being admitted 

 by all the best authorities that neither similarity of mineral 

 composition, nor of physical character, nor even direct 

 continuity of stratum, are absolute proofs of the synchronism 

 of even approximated sedimentary strata : while, for 

 distant deposits, there seems to be no kind of physical 

 evidence attainable of a nature competent to decide 



