x/j GEOLOGICAL CONTEMPORANEITY. 185 



of an undisturbed series of sedimentary deposits, the bed which 

 lies lowest is the oldest. In many other vertical linear sections 

 of the same series, of course, corresponding beds will occur in a 

 similar order ; but, however great may be the probability, no man 

 can say with absolute certainty that the beds in the two sections 

 were synchronously deposited. For areas of moderate extent, 

 it is doubtless time that no practical evil is likely to result from 

 assuming the corresponding beds to be synchronous or strictly 

 contemporaneous ; and there are multitudes of accessory circum 

 stances which may fully justify the assumption of such synchrony. 

 But the moment the geologist has to deal with large areas, or 

 with completely separated deposits, the mischief of confounding 

 that &quot; homotaxis &quot; or &quot; similarity of arrangement,&quot; which can be 

 demonstrated, with &quot; synchrony &quot; or &quot; identity of date,&quot; for 

 which there is not a shadow of proof, under the one common 

 term of &quot; contemporaneity &quot; becomes incalculable, and proves the 

 constant source of gratuitous speculations. 



For anything that geology or palaeontology are able to show to 

 the contrary, a Devonian fauna and flora in the British Islands 

 may have been contemporaneous with Silurian life in North 

 America, and with a Carboniferous fauna and flora in Africa. 

 Geographical provinces and zones may have been as distinctly 

 marked in the Palaeozoic epoch as at present, and those seemingly 

 sudden appearances of new genera and species, which we ascribe 

 to new creation, may be simple results of migration. 



It may be so ; it may be otherwise. In the present condition 

 of our knowledge and of our methods, one verdict &quot; not proven, 

 and not proveable &quot; must be recorded against all the grand 

 hypotheses of the palaeontologist respecting the general succession 

 of life on the globe. The order and nature of terrestrial life, as 

 a whole, are open questions. Geology at present provides us 

 with most valuable topographical records, but she has not the 

 means of working them into a universal history. Is such a 

 universal history, then, to be regarded as unattainable ? Are all 

 the grandest and most interesting problems which offer them 

 selves to the geological student essentially insoluble ? Is he in 



